UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549





FORM 40-F





(Check One)

|☐ | Registration statement pursuant to Section 12 of the Securities Exchange Act of 1934
|- | ------------------------------------------------------------------------------------



|☒ | Annual report pursuant to Section 13(a) or 15(d) of the Securities Exchange Act of 1934
|- | ---------------------------------------------------------------------------------------



|                                             |  |                                  
|-------------------------------------------- |  | ---------------------------------
|For the fiscal year ended: December 31, 2016 |  | Commission file number: 001-33414





DENISON MINES CORP.

(Exact name of registrant as specified in its charter)





Ontario,
Canada

(Province or other jurisdiction of incorporation or organization)

1090

(Primary standard
industrial classification code number)

98-0622284

(I.R.S. employer identification number)

1100  40 University Avenue, Toronto, Ontario M5J 1T1 Canada; Phone number: 416-979-1991

(Address and telephone number of registrants principal executive offices)

C T Corporation System

111 Eighth Avenue

13th Floor

New York, NY 10011

Phone number: 212-894-8800

(Name, address and telephone number of agent for service in the United States)

Securities registered pursuant to Section 12(b) of the Act: Not applicable.

Securities registered pursuant to Section 12(g) of the Act: Common Shares without par value.

Securities for which there is a reporting obligation pursuant to Section 15(d) of the Act: Not applicable.

For annual reports, indicate by check mark the information filed with this form:



|                         |  |                                     
|------------------------ |  | ------------------------------------
|☒Annual Information Form |  | ☐Audited Annual Financial Statements





Indicate the number of outstanding shares of each of the issuers classes of capital or common stock as of the close of the period covered by the annual
report: 540,722,365 Common Shares as at December 31, 2016.

Indicate by check mark whether the registrant: (1) has filed all reports
required to be filed by Section 13(d) or 15(d) of the Exchange Act during the preceding 12 months (or for such shorter period that the registrant has been required to file such reports); and (2) has been subject to such filing
requirements in the past 90 days.

Yes   ☒             No   ☐

Indicate by check mark whether the registrant has submitted electronically and posted on its corporate Web site, if any, every Interactive Data File required
to be submitted and posted pursuant to Rule 405 of Regulation S-T (232.405 of this chapter) during the preceding 12 months (or for such shorter period that the Registrant was required to submit and post such files). Not applicable

Yes   ☐             No   ☐









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DOCUMENTS FILED PURSUANT TO GENERAL INSTRUCTIONS

In accordance with General Instruction B.(3) of Form 40-F, Denison Mines Corp. (the Company or the Registrant) hereby
incorporates by reference Exhibits 99.1 through 99.3 as set forth in the Exhibit Index attached hereto.

In accordance with General Instruction D.(9) of
Form 40-F, the Company has filed written consents of certain experts named in the foregoing Exhibits as Exhibits 99.4 through 99.17, as set forth in the Exhibit Index attached hereto.

FORWARD-LOOKING STATEMENTS

Certain of
the information contained in this Annual Report on Form 40-F, including the documents incorporated herein by reference, may contain forward-looking information. Forward-looking information and statements may include, among others,
statements regarding the future plans, costs, objectives or performance of the Company, or the assumptions underlying any of the foregoing. In this Annual Report on Form 40-F, words such as may, would, could,
will, likely, believe, expect, anticipate, intend, plan, estimate and similar words and the negative form thereof are used to identify forward-looking
statements. Forward-looking statements should not be read as guarantees of future performance or results, and will not necessarily be accurate indications of whether, or the times at or by which, such future performance will be achieved.
Forward-looking statements and information are based on information available at the time and/or managements good-faith belief with respect to future events and are subject to known or unknown risks, uncertainties and other unpredictable
factors, many of which are beyond the Companys control. These risks, uncertainties and assumptions include, but are not limited to, those described under the section Risk Factors in the Companys Annual Information Form for
the fiscal year ended December 31, 2016 (the AIF), which is filed as Exhibit 99.3 to this Annual Report on Form 40-F, and could cause actual events or results to differ materially from those projected in any forward-looking
statements.

The Companys forward-looking statements contained in the exhibits incorporated by reference into this Annual Report on Form 40-F are
made as of the respective dates set forth in such exhibits. In preparing this Annual Report on Form 40-F, the Company has not updated such forward-looking statements to reflect any subsequent information, events or circumstances or otherwise, or any
change in managements beliefs, expectations or opinions that may have occurred prior to the date hereof, nor does the Company assume any obligation to update such forward-looking statements in the future, except as required by applicable laws.

RESOURCE AND RESERVE ESTIMATES

The
terms mineral reserve, proven mineral reserve and probable mineral reserve are Canadian mining terms as defined in accordance with National Instrument 43-101  Standards of Disclosure for Mineral Projects
(NI 43-101), which references the guidelines set out in the Canadian Institute of Mining, Metallurgy and Petroleum (the CIM) Standards on Mineral Resources and Mineral Reserves, adopted by the CIM council, as
may be amended from time to time by the CIM. These definitions differ from the definitions in Industry Guide 7 (Industry Guide 7) under the United States Securities Act of 1933, as amended. Under Industry Guide 7, mineralization
may not be classified as a reserve unless the determination has been made that the mineralization could be economically and legally produced or extracted at the time of the reserve determination.

In addition, the terms mineral resource, measured mineral resource, indicated mineral resource and inferred mineral
resource are defined in and required to be disclosed by NI 43-101; however, these terms are not defined terms under Industry Guide 7 and normally are not permitted to be used in reports and registration statements filed with the Securities and
Exchange Commission (the SEC or the Commission). Investors are cautioned not to assume that any part or all of mineral deposits in these categories will ever be converted into reserves. Inferred mineral
resources have a great amount of uncertainty as to their existence, and great uncertainty as to their economic and legal feasibility. It cannot be assumed that all or any part of an inferred mineral resource will ever be upgraded to a higher
category. Under Canadian rules, estimates of inferred mineral resources may not form the basis of feasibility or pre-feasibility studies, except in rare cases.



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Accordingly, information contained in this Annual Report on Form 40-F and the documents incorporated by reference
herein containing descriptions of the Companys mineral deposits may not be comparable to similar information made public by U.S. companies subject to the reporting and disclosure requirements under the United States federal securities laws and
the rules and regulations thereunder.

CURRENCY

Unless otherwise indicated, all dollar amounts in this Annual Report on Form 40-F are in United States dollars. The exchange rate of Canadian dollars into
United States dollars, on December 31, 2016, based upon the noon buying rate payable in Canadian dollars as certified for customs purposes by the Bank of Canada, was U.S. $1.00 = CDN$0.75.

TAX MATTERS

Purchasing, holding, or
disposing of securities of the Registrant may have tax consequences under the laws of the United States and Canada that are not described in this Annual Report on Form 40-F.

DISCLOSURE CONTROLS AND PROCEDURES

A.
  Evaluation of Disclosure Controls and Procedures

The Company maintains disclosure controls and procedures to ensure that information
required to be disclosed in the Companys filings under the Securities Exchange Act of 1934, as amended (the Exchange Act), is recorded, processed, summarized and reported in accordance with the requirements specified in the
rules and forms of the SEC. The Company carried out an evaluation, under the supervision and with the participation of its management, including the Chief Executive Officer and Chief Financial Officer, of the effectiveness of the design and
operation of the Companys disclosure controls and procedures (as defined in the Exchange Act Rule 13a-15(e)) as of the end of the period covered by this report. Based upon that evaluation, the Chief Executive Officer and Chief
Financial Officer concluded that the Companys disclosure controls and procedures as of December 31, 2016 are effective to ensure that information required to be disclosed by the Registrant in reports it files or submits under the Exchange
Act is recorded, processed, summarized and reported within the time periods specified in the SECs rules and forms and is accumulated and communicated to the Registrants management, including its Chief Executive Officer and Chief
Financial Officer, as appropriate to allow timely decisions regarding required disclosure.

The Companys disclosure controls and procedures are
designed to provide reasonable assurance of achieving their objectives and, as indicated in the preceding paragraph, the Chief Executive Officer and Chief Financial Officer believe that the Companys disclosure controls and procedures are
effective at that reasonable assurance level, although the Chief Executive Officer and Chief Financial Officer do not expect that the disclosure controls and procedures or internal control over financial reporting will prevent or detect all errors
and all fraud. A control system, no matter how well conceived or operated, can provide only reasonable, not absolute, assurance that the objectives of the control system are met. The Company will continue to periodically review its disclosure
controls and procedures and internal control over financial reporting and may make such modifications from time to time as it considers necessary.

B.
  Managements Annual Report on Internal Control Over Financial Reporting

The Companys management is responsible for establishing
and maintaining an adequate system of internal control over financial reporting. Internal control over financial reporting is a process designed to provide reasonable assurance regarding the reliability of the Companys financial reporting and
the preparation of financial statements for external purposes in accordance with International Financial Reporting Standards. Management conducted an assessment of the Companys internal control over financial reporting based on the framework
established by the Committee of Sponsoring Organizations of the Treadway Commission on Internal Control  Integrated Framework (2013). Based on this assessment, management concluded that, as of December 31, 2016, the Companys
internal control over financial reporting is effective.



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C.   Report of the Independent Auditor, PricewaterhouseCoopers LLP

The effectiveness of the Registrants internal control over financial reporting as of December 31, 2016 has been audited by PricewaterhouseCoopers
LLP, an independent auditor, as stated in their report included with the Registrants Audited Financial Statements, which are an exhibit to this Annual Report on Form 40-F.

D.   Changes in Internal Control Over Financial Reporting

There was no change in the Companys internal control over financial reporting that occurred during the twelve month period covered by this Annual Report
that has materially affected, or is reasonably likely to materially affect, the Companys internal control over financial reporting.

CORPORATE GOVERNANCE

The Company is
listed on the Toronto Stock Exchange (the TSX) and is required to describe its practices and policies with regard to corporate governance with specific reference to the corporate governance guidelines of the Canadian Securities
Administrators on an annual basis by way of a corporate governance statement contained in the Companys Annual Information Form or Information Circular. The Company is also listed on the NYSE MKT LLC (the NYSE MKT) and
additionally complies as necessary with the rules and guidelines of the NYSE MKT as well as the SEC. The Company reviews its governance practices on an ongoing basis to ensure it is in compliance with the applicable laws, rules and guidelines both
in Canada and in the United States.

The Companys Board of Directors (the Board) is responsible for the Companys corporate
governance policies and has separately designated a standing Corporate Governance and Nominating Committee. The Board has determined that the members of the Corporate Governance and Nominating Committee are independent, based on the criteria for
independence and unrelatedness prescribed by the Sarbanes-Oxley Act of 2002, Section 10A(m)(3), and the NYSE MKT.

Corporate governance relates to
the activities of the Board, the members of which are elected by and are accountable to the shareholders, and takes into account the role of the senior officers who are appointed by the Board and who are charged with the day to day administration of
the Company. The Board is committed to sound corporate governance practices that are both in the interest of its shareholders and contribute to effective and efficient decision making.

BENEFIT PLAN BLACKOUT PERIODS

Not
applicable.



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AUDIT COMMITTEE FINANCIAL EXPERT

The Companys Board of Directors has determined that all three members of its Audit Committee (Ms. Catherine Stefan, Mr. Brian D. Edgar and
Mr. William A. Rand) are audit committee financial experts, within the meaning of paragraph 8(b) of General Instruction B of Form 40-F, and are also independent within the meaning of United States and Canadian securities regulations and
applicable stock exchange requirements. A description of the education and experience of these persons is set forth in the table below:



|                                                    |                                                                                                                                                                                                                                                 |                                                                                                                            
|--------------------------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------------------------------------------------
|Member Name                                         |                                                                                                                                                                                                                                                 | Education & experience relevant to
performance of audit committee duties                                                   
|Catherine J.G. Stefan,
Chair of the Audit
Committee |                                                                                                                                                                                                                                                 |     Chartered Professional Accountant (Chartered Accountant)                                                              
|                                                    |     B.Comm                                                                                                                                                                                                                                    
|                                                    |     Held position of Chief Operating Officer of O&Y Properties
Inc., President of Stefan & Associates and Executive Vice-President of Bramalea Group, Chair, Tax Committee of the Canadian Institute of Public Real Estate Companies (CIPREC).
|Brian D. Edgar                                      |                                                                                                                                                                                                                                                 |     Law degree, with extensive corporate finance experience                                                               
|                                                    |                                                                                                                                                                                                                                                 |     Held positions of Chairman since 2011 and President and Chief
Executive Officer of a public company from 2005 to 2011.
|                                                    |                                                                                                                                                                                                                                                 |     Has served on audit committees of a number of public companies                                                        
|William A. Rand                                     |                                                                                                                                                                                                                                                 |     B.Comm (Accounting)                                                                                                   
|                                                    |                                                                                                                                                                                                                                                 |     Two law degrees, with extensive corporate finance experience                                                          
|                                                    |                                                                                                                                                                                                                                                 |     Has served on audit committees of a number of public
companies                                                        

Through such education and experience, each of these three members has experience overseeing and assessing the performance of
companies and public accountants with respect to the preparation, auditing and evaluation of financial statements, and has: (1) an understanding of generally accepted accounting principles and financial statements; (2) the ability to
assess the general application of such principles in connection with the accounting for estimates, accruals and reserves; (3) experience preparing, auditing, analyzing or evaluating financial statements that present a breadth and level of
complexity of accounting issues that are generally comparable to the breadth and complexity of issues that can reasonably be expected to be raised by the Companys financial statements; (4) an understanding of internal control over
financial reporting; and (5) an understanding of audit committee functions.

The SEC has provided that the designation of an audit committee
financial expert does not make him or her an expert for any purpose, impose on him or her any duties, obligations or liability that are greater than the duties, obligations or liability imposed on him or her as a member of the Audit
Committee and the Board in the absence of such designation, or affect the duties, obligations or liability of any other member of the Audit Committee or Board.

CODE OF ETHICS

The Company has adopted a
code of ethics that applies to the Companys directors, officers and employees, including the Chief Executive Officer, Chief Financial Officer, principal accounting officer or controller, persons performing similar functions and other officers,
directors and employees of the Company. A current copy of the amended code of ethics is on the Companys website at www.denisonmines.com. In the fiscal year ended December 31, 2016, the Company has not made any amendment to a provision of
its code of ethics that applies to any of its Chief Executive Officer, Chief Financial Officer, principal accounting officer or controller or persons performing similar functions that relates to one or more of the items set forth in paragraph
(9)(b) of General Instruction B to Form 40-F. In the fiscal year ended December 31, 2016, the Company has not granted a waiver (including an implicit waiver) from a provision of its code of ethics to any of its Chief Executive Officer,
Chief Financial Officer, principal accounting officer or controller or persons performing similar functions that relates to one or more of the items set forth in paragraph (9)(b) of General Instruction B to Form 40-F.



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PRINCIPAL ACCOUNTANT FEES AND SERVICES

The following table discloses the fees billed to the Company by its external auditor during the last two financial years ended December 31, 2016 and
2015. Services were billed and paid in Canadian dollars and have been translated into U.S. dollars using an average CAD$/US$ annual exchange rate of $1.3245 for 2016 and $1.2785 for 2015.



|                  |  |               |         |  |                       |   |         |             |  |   |                   |  |  |   |        | 
|----------------- |  | ------------- | ------- |  | --------------------- | - | ------- | ----------- |  | - | ----------------- |  |  | - | ------ | 
|Periods Ending    |  | Audit Fees(1) |         |  | Audit Related Fees(2) |   |         | Tax Fees(3) |  |   | All Other Fees(4) | 
|December 31, 2015 |  | $             | 195,586 |  |                       | $ | 107,351 |             |  | $ | 0                 |  |  | $ | 59,286 | 
|December 31, 2016 |  | $             | 132,871 |  |                       | $ | $97,379 |             |  | $ | 0                 |  |  | $ | 0      | 

Notes:



|(1) | The aggregate fees billed for audit services of the Companys consolidated financial statements.
|--- | ------------------------------------------------------------------------------------------------

|(2) | The aggregate fees billed for assurance and related services that are reasonably related to the performance of the audit or review of the Companys financial statements and are not disclosed in the Audit Fees
column. Fees relate to reviews of interim consolidated financial statements and specified audit procedures not included as part of the audit of the consolidated financial statements.
|--- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

|(3) | The aggregate fees billed for tax compliance, tax advice, and tax planning services, such as transfer pricing and tax return preparation.
|--- | -----------------------------------------------------------------------------------------------------------------------------------------

|(4) | The aggregate fees billed for professional services other than those listed in the other three columns. For 2015, All Other Fees relates to special project costs.
|--- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------

The Companys Audit Committee mandate and charter provides that the Audit Committee shall (i) approve, prior to the auditors audit, the
auditors audit plan (including, without limitation, staffing), the scope of the auditors review and all related fees, and (ii) pre-approve any non-audit services (including, without limitation, fees therefor) provided to the Company
or its subsidiaries by the auditor or any auditor of any such subsidiary and shall consider whether these services are compatible with the auditors independence, including, without limitation, the nature and scope of the specific non-audit
services to be performed and whether the audit process would require the auditor to review any advice rendered by the auditor in connection with the provision of non-audit services.

The following sets forth the percentage of services described above that were approved by the audit committee pursuant to paragraph (c)(7)(i)(C) of Rule 2-01
of Regulation S-X:



|                    |  |      |     |   |      |  |     |  
|------------------- |  | ---- | --- | - | ---- |  | --- | -
|                    |  | 2015 |     |   | 2016 | 
|Audit Related Fees: |  |      | 100 | % |      |  | 100 | %
|Tax Fees:           |  |      | 100 | % |      |  | 100 | %
|All Other Fees:     |  |      | 100 | % |      |  | 100 | %

OFF-BALANCE SHEET ARRANGEMENTS

The Company does not have any off-balance sheet arrangements at December 31, 2016 and at the date hereof.

TABULAR DISCLOSURE OF CONTRACTUAL OBLIGATIONS

At December 31, 2016, the Company had a reclamation liability of $20,965,000, consisting of $12,470,000 for Elliot Lake obligations, $8,479,000 for the
McClean Lake and Midwest joint ventures obligations and $16,000 for other obligations. The Company maintains a trust fund equal to the estimated reclamation spending for the succeeding six calendar years, less interest expected to accrue on the
funds, in respect of its liability for Elliot Lake. At December 31, 2016, the balance in the trust fund was US$2,213,000.



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In addition, the Companys contractual obligations at December 31, 2016 are as follows:



|                                      |  |       |           |  |        |  |         |           |  |  |           |  |  |              |         |  |  |  |         | 
|------------------------------------- |  | ----- | --------- |  | ------ |  | ------- | --------- |  |  | --------- |  |  | ------------ | ------- |  |  |  | ------- | 
|(in thousands)                        |  | Total |           |  | 1 Year |  |         | 2-3 Years |  |  | 4-5 Years |  |  | After5 Years |        
|Debt Obligations                      |  | $     | 276,000   |  |        |  | 276,000 |           |  |  |          |  |  |              |        |  |  |  |        | 
|Operating lease and other obligations |  | $     | 1,092,000 |  |        |  | 182,000 |           |  |  | 318,000   |  |  |              | 286,000 |  |  |  | 306,000 | 

IDENTIFICATION OF THE AUDIT COMMITTEE

The Company has a separately-designated standing audit committee established in accordance with Section 3(a)(58)(A) of the Exchange Act. The
committee members are Ms. Catherine J. G. Stefan and Messrs. Brian D. Edgar and William A. Rand. For further information on these members, see discussion above under Audit Committee Financial Experts.

INTERACTIVE DATA FILE

An interactive
data file is not yet required to be filed since the Company prepares its financial statements in accordance with International Financial Reporting Standards.

NYSE MKT CORPORATE GOVERNANCE

The
Companys common shares are listed on the NYSE MKT. Section 110 of the NYSE MKT Company Guide permits the NYSE MKT to consider the laws, customs and practices of foreign issuers in relaxing certain NYSE MKT listing criteria, and to grant
exemptions from the NYSE MKT listing criteria based on these considerations. An issuer seeking relief under these provisions is required to provide written certification from independent local counsel that the non-complying practice is not
prohibited by home country law. A description of the significant ways in which the Companys governance practices differ from those followed by domestic companies pursuant to the NYSE MKT standards is as follows:

Board Composition: The NYSE MKT requires that a listed company have a Board of Directors consisting of at least a majority of members who satisfy
applicable independence standards under Section 803 of the NYSE MKT Company Guide (the NSYE MKT Independence Standard). The Companys Board is currently composed of seven members, four of whom qualify as independent
under the NYSE MKT Company Guide and who meet the NSYE MKT Independence Standard, namely Ms. Stefan and Messrs. Dengler, Edgar and Rand. Denisons remaining three directors do not satisfy the NYSE MKT Independence Standard, being Messrs.
Hochstein, Lundin and Jeong.

Shareholder Meeting Quorum Requirement: The NYSE MKT minimum quorum requirement for a shareholder meeting is
one-third of the shares issued and outstanding and entitled to vote for a meeting of a listed companys shareholders. The TSX does not specify a quorum requirement for a meeting of a listed companys shareholders. The Companys
current required quorum at any meeting of shareholders as set forth in the Companys by-laws is two persons present, each being a shareholder entitled to vote at the meeting or a duly appointed proxyholder for an absent shareholder so entitled,
holding or representing in aggregate not less than 10% of the shares of the Company entitled to be voted at the meeting. The Companys current quorum requirement is not prohibited by, and does not constitute a breach of, the Business
Corporations Act (Ontario) (the OBCA), applicable Canadian securities laws or the rules and policies of the TSX.

Proxy
Solicitation Requirement: The NYSE MKT requires the solicitation of proxies and delivery of proxy statements for all shareholder meetings of a listed company, and requires that these proxies be solicited pursuant to a proxy statement that
conforms to the proxy rules of the U.S. Securities and Exchange Commission. The Company is a foreign private issuer as defined in Rule 3b-4 under the Exchange Act, and the equity securities of the Company are accordingly exempt from the proxy rules
set forth in Sections 14(a), 14(b), 14(c) and 14(f) of the Exchange Act. The Company solicits proxies in accordance with the OBCA, applicable Canadian securities laws and the rules and policies of the TSX.



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Shareholder Approval Requirements: The NYSE MKT requires a listed company to obtain the approval of its
shareholders for certain types of securities issuances. One is the sale of common shares (or securities convertible into common shares) at a discount to officers or directors. The TSX rules require shareholder approval for the issuance of shares to
insiders in private placements where insiders are being issued more than 10% of the presently issued and outstanding shares. The NYSE MKT also requires shareholder approval of private placements that may result in the issuance of common shares (or
securities convertible into common shares) equal to 20% or more of presently outstanding shares for less than the greater of book or market value of the shares. There is no such requirement under Ontario law. The TSX rules require shareholder
approval for private placements that materially affect control, or where more than 25% of presently issued and outstanding shares will be issued at a discount to market. The Company will seek a waiver from the NYSE MKT shareholder approval
requirement should a dilutive securities issuance trigger such NYSE MKT shareholder approval requirement in circumstances where such securities issuance does not trigger a shareholder approval requirement under the rules of the TSX.

Compensation Committee Requirements: The NYSE MKT Company Guide requires that additional independence criteria be applied to each member
of the Compensation Committee. The NYSE MKT Company Guide also mandates that the Compensation Committee must have the authority to hire compensation consultants, independent legal counsel and other compensation advisors and exercise the sole
responsibility to oversee the work of any compensation advisors retained to advise the Compensation Committee. In addition, before engaging a compensation advisor, the Compensation Committee must consider at least six factors that could potentially
impact compensation advisor independence. The Company follows Canadian Securities Administrators and TSX requirements for Compensation Committee charters, independence and authority. The Compensation Committees Charter includes a requirement
that each member of the Compensation Committee be independent and that the Compensation Committee have the authority to retain outside advisors and determine the extent of funding necessary for payment of consultants.

The foregoing are consistent with the laws, customs and practices in Canada.

In addition, the Company may from time-to-time seek relief from the NYSE MKT corporate governance requirements on specific transactions under Section 110
of the NYSE MKT Company Guide by providing written certification from independent local counsel that the non-complying practice is not prohibited by its home country law, in which case, the Company shall make the disclosure of such transactions
available on its website at www.denisonmines.com. Information contained on, or accessible through, our website is not part of this Annual Report.

MINE SAFETY DISCLOSURE

Not applicable.

UNDERTAKING AND CONSENT TO SERVICE OF PROCESS

A.   Undertaking

The Company undertakes to
make available, in person or by telephone, representatives to respond to inquiries made by the Commission staff, and to furnish promptly, when requested to do so by the Commission staff, information relating to: the securities registered pursuant to
Form 40-F; the securities in relation to which the obligation to file an Annual Report on Form 40-F arises; or transactions in said securities.



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B.   Consent to Service of Process

The Company has previously filed with the SEC a Form F-X in connection with its common stock. Any change to the name or address of the Companys agent for
service shall be communicated promptly to the SEC by amendment to the Form F-X referencing the file number of the Company.



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SIGNATURES

Pursuant to the requirements of the Exchange Act, the Company certifies that it meets all of the requirements for filing on Form 40-F and has duly caused this
Annual Report to be signed on its behalf by the undersigned, thereto duly authorized.



|                                |  |                                      
|------------------------------- |  | -------------------------------------
|Registrant: DENISON MINES CORP.
|                                | 
|By:                             |  | /s/ David D. Cates                   
|Title:                          |  | President and Chief Executive Officer
|Date:                           |  | March 30, 2017                       



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EXHIBIT INDEX



|      |  |                                                                                                                                                                                                                                                                      
|----- |  | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
|      | 
|99.1  |  | Annual Information Form for the Year Ended December 31, 2016                                                                                                                                                                                                         
|      | 
|99.2  |  | Managements Discussion and Analysis of Results of Operations and Financial Condition for the Year ended December 31, 2016 (incorporated by reference to Exhibit 99.3 of the Registrants Form 6-K furnished to the Commission
on March 9, 2017)                     
|      | 
|99.3  |  | Consolidated Audited Financial Statements for the Years Ended December 31, 2016 and 2015 together with the Independent Auditors Report thereon (incorporated by reference to Exhibit 99.2 of the Registrants Form 6-K
furnished to the Commission on March 9, 2017)
|      | 
|99.4  |  | Consent of PricewaterhouseCoopers LLP                                                                                                                                                                                                                                
|      | 
|99.5  |  | Officers Certifications Required by Rule 13a-14(a) or Rule 15d-14(a) of the Securities Exchange Act of 1934                                                                                                                                                         
|      | 
|99.6  |  | Officers Certifications Required by Rule 13a-14(b) or Rule 15d-14(b) and Section 1350 of Chapter 63 of Title 18 of the United States Code                                                                                                                           
|      | 
|99.7  |  | Consent of Roscoe Postle Associates Inc.                                                                                                                                                                                                                             
|      | 
|99.8  |  | Consent of Leo R. Hwozdyk, P.Eng.                                                                                                                                                                                                                                    
|      | 
|99.9  |  | Consent of Luke Evans, M.Sc., P.Eng.                                                                                                                                                                                                                                 
|      | 
|99.10 |  | Consent of Richard E. Routledge, M. Sc., P.Geol.                                                                                                                                                                                                                     
|      | 
|99.11 |  | Consent of SGS Canada Inc. (formerly Geostat Systems International Inc.)                                                                                                                                                                                             
|      | 
|99.12 |  | Consent of Michel Dagbert, P.Eng. (Retired)                                                                                                                                                                                                                          
|      | 
|99.13 |  | Consent of GeoVector Management Inc.                                                                                                                                                                                                                                 
|      | 
|99.14 |  | Consent of Allan Armitage, Ph.D., P.Geol.                                                                                                                                                                                                                            
|      | 
|99.15 |  | Consent of Alan Sexton, M.Sc., P.Geol.                                                                                                                                                                                                                               
|      | 
|99.16 |  | Consent of SRK Consulting (Canada) Inc.                                                                                                                                                                                                                              
|      | 
|99.17 |  | Consent of Ken Reipas, P.Eng.