thumb|350px|[[Constitution of 3 May 1791 (painting)|3 May Constitution, by Matejko, 1891. King Stanisław August (left, in regal ermine-trimmed cloak), enters St. John's Cathedral, where Sejm deputies will swear to uphold the new Constitution. In background, Warsaw's Royal Castle, where the Constitution has just been adopted.]]
The Patriotic Party (), also known as the Patriot Party or, in English, as the Reform Party, was a political movement in the Polish–Lithuanian Commonwealth in the period of the Four-Year Sejm (Great Sejm) of 1788–1792, whose chief achievement was the Constitution of 3 May 1791.