UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): July 2, 2013

POLONIA BANCORP, INC.

(Exact name of registrant as specified in its charter)

(215) 938-8800

(Registrant’s telephone number, including area code)

Not Applicable

(Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

¨ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

¨ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

¨ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

¨ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

On July 2, 2013, the Company announced that it has authorized the funding of a trust that will purchase up to 68,294 shares of the Company’s outstanding common stock. The shares acquired by the trust will be used to fund restricted stock awards under the Company’s 2013 Equity Incentive Plan, which was approved by shareholders at the Company’s annual meeting held on May 21, 2013. For more information, reference is made to the Company’s press release dated July 2, 2013, a copy of which is attached to this Report as Exhibit 99.1 and is furnished herewith.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned thereunto duly authorized.