3 May Constitution Day (Polish: Święto Konstytucji 3 Maja) is a major Polish national public holiday celebrated annually on May 3 to commemorate the adoption of the Constitution of May 3, 1791. This document is recognized as Europe’s first modern constitution and the world’s second-oldest written national constitution, following only the United States Constitution of 1789.

The holiday honors a progressive political reform that established a constitutional monarchy, separated powers, and aimed to strengthen the Polish-Lithuanian Commonwealth against external threats. Although the constitution was in effect for less than two years before being annulled following the Russo-Polish War of 1792, it remains a powerful symbol of Polish national identity, democracy, and resilience.

Key Facts
- Status: Official national public holiday in Poland since 1919 (with interruptions during partitions, WWII, and the communist era; restored in 1990).
- Significance: Marks the culmination of nearly half a century of reform efforts in the Polish-Lithuanian Commonwealth.
- Celebrations: Includes military parades, patriotic concerts, flag flying, and official ceremonies at the Tomb of the Unknown Soldier in Warsaw.
- Cultural Context: Part of the Majówka holiday season, which also includes May 1 (Labor Day) and May 2 (Flag Day), often involving family gatherings, picnics, and traditional grilling.
- Global Observance: Celebrated by Polish diaspora communities worldwide, notably with annual parades in Chicago and other cities with significant Polish populations.

