Constitution Day is a national public holiday in Poland celebrated on 3rd May. This day commemorates the adoption of the Constitution of May 3, 1791, which has a special place in the Polish national identity as it was the first in Europe and second in the world modern constitution. This political document was a significant achievement in the history of the Polish-Lithuanian Commonwealth as it aimed to balance the power and protect civil liberties.

In spite of the profound changes introduced by this Constitution, it did not necessarily bring peace and prosperity to the country. After being in force for only 14 months, it was annulled following the Russian Empire's invasion. Constitution Day as a holiday was introduced under the second Polish Republic in 1919, but it was banned during the WWII and the communist regime times as well. It was finally restored after the fall of communism in April 1990.

Today, the day is marked with patriotic events, military parades, cultural and educational activities, which all highlight the importance of this crucial historical moment. The highest authorities participate in official celebrations taking place in Warsaw, including the traditional change of guards at the Tomb of the Unknown Soldier. It is a day to reflect on the core values of democracy, the importance of statehood, and the unique character of Polish history.