**Exhibit 99.1**

 

**Certification of Chief Executive Officer Pursuant to Rule 13a-14(a) or 15d-14(a) of the Securities Exchange Act of 1934**

 

I, Brian C. Ferguson, certify that:

 
| 1.     |   | I   have reviewed this annual report on Form 40-F of Cenovus Energy Inc.;                                                                                                                                                                                                                                                                                          |
|--------|--------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
|   |   |                                                                                                                                                                                                                                                                                                                                                                    |
| 2.     |   | Based   on my knowledge, this report does not contain any untrue statement of a   material fact or omit to state a material fact necessary to make the   statements made, in light of the circumstances under which such statements   were made, not misleading with respect to the period covered by this report;                                                      |
|   |   |                                                                                                                                                                                                                                                                                                                                                                    |
| 3.     |   | Based   on my knowledge, the financial statements, and other financial information   included in this report, fairly present in all material respects the   financial condition, results of operations and cash flows of the issuer as   of, and for, the periods presented in this report;                                                                             |
|   |   |                                                                                                                                                                                                                                                                                                                                                                    |
| 4.     |   | The   issuer’s other certifying officer(s) and I are responsible for   establishing and maintaining disclosure controls and procedures (as defined   in Exchange Act Rules 13a-15(e) and 15d-15(e)) and internal control   over financial reporting (as defined in Exchange Act   Rules 13a-15(f) and 15d-15(f)) for the issuer and have: |
|   |   |                                                                                                                                                                                                                                                                                                                                                                    |
|   |   | (a)                                                                                                                                                                                                                                                                                                                                                                     | Designed   such disclosure controls and procedures, or caused such disclosure controls   and procedures to be designed under our supervision, to ensure that material   information relating to the issuer, including its consolidated subsidiaries,   is made known to us by others within those entities, particularly during the   period in which this report is being prepared; |
|   |   |                                                                                                                                                                                                                                                                                                                                                                    |   |
|   |   | (b)                                                                                                                                                                                                                                                                                                                                                                     | Designed   such internal control over financial reporting, or caused such internal   control over financial reporting to be designed under our supervision, to   provide reasonable assurance regarding the reliability of financial reporting   and the preparation of financial statements for external purposes in   accordance with generally accepted accounting principles; |
|   |   |                                                                                                                                                                                                                                                                                                                                                                    |   |
|   |   | (c)                                                                                                                                                                                                                                                                                                                                                                     | Evaluated   the effectiveness of the issuer’s disclosure controls and procedures and   presented in this report our conclusions about the effectiveness of the   disclosure controls and procedures, as of the end of the period covered by   this report based on such evaluation; and |
|   |   |                                                                                                                                                                                                                                                                                                                                                                    |   |
|   |   | (d)                                                                                                                                                                                                                                                                                                                                                                     | Disclosed   in this report any change in the issuer’s internal control over financial   reporting that occurred during the period covered by the annual report that   has materially affected, or is reasonably likely to materially affect, the   issuer’s internal control over financial reporting; and |
|   |   |                                                                                                                                                                                                                                                                                                                                                                    |   |
| 5.     |   | The   issuer’s other certifying officer(s) and I have disclosed, based on our   most recent evaluation of internal control over financial reporting, to the   issuer’s auditors and the audit committee of the issuer’s board of directors   (or persons performing the equivalent functions):                                                      |
|   |   |                                                                                                                                                                                                                                                                                                                                                                    |   |
|   |   | (a)                                                                                                                                                                                                                                                                                                                                                                     | All   significant deficiencies and material weaknesses in the design or operation   of internal control over financial reporting which are reasonably likely to   adversely affect the issuer’s ability to record, process, summarize and   report financial information; and |
|   |   |                                                                                                                                                                                                                                                                                                                                                                    |   |
|   |   | (b)                                                                                                                                                                                                                                                                                                                                                                     | Any   fraud, whether or not material, that involves management or other employees   who have a significant role in the issuer’s internal control over financial   reporting. |

 

 
| Date: February 13, 2015                 |   |
|----------------------------------------------|--------|
|                                         |   |
| /s/ Brian C. Ferguson                        |   |
| Brian C. Ferguson                            |   |
| President & Chief Executive Officer |   |
| (Principal Executive Officer)                |   |

 

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