Exhibit
31.2



CERTIFICATION
PURSUANT TO 18 U.S.C. §1350,

AS ADOPTED PURSUANT
TO SECTION 302 OF THE SARBANES-OXLEY ACT OF 2002



Certification



I, Joseph A. Geraci, II,
certify that:



| | 1. | I have reviewed this Quarterly Report
                                         on Form 10-Q of Mill City Ventures III, Ltd.;
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| | 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;
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| | 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 registrant as of, and for, the periods presented in this report;
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| | 4. | The registrant’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 registrant and have:
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| | (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 registrant, 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;
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| | (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;
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| | (c) | Evaluated the effectiveness of the
                                         registrant’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
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| | (d) | Disclosed in this report any change
                                         in the registrant’s internal control over financial reporting that occurred during
                                         the registrant’s most recent fiscal quarter (the registrant’s fourth fiscal
                                         quarter in the case of an annual report) that has materially affected, or is reasonably
                                         likely to materially affect, the registrant’s internal control over financial reporting;
                                         and
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| | 5. | The registrant’s other certifying
                                         officer(s) and I have disclosed, based on our most recent evaluation of internal control
                                         over financial reporting, to the registrant’s auditors and the audit committee
                                         of the registrant’s board of directors (or persons performing the equivalent functions):
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| | (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 registrant’s ability to record, process,
                                         summarize and report financial information; and
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| | (b) | Any fraud, whether or not material,
                                         that involves management or other employees who have a significant role in the registrant’s
                                         internal control over financial reporting.
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|Dated: May 12, 2015 | /s/ Joseph A. Geraci, II
|------------------- | ------------------------
|                    | JosephA. Geraci, II     
|                    | Chief Financial Officer