Martyr's Day, or 'Día de los Mártires' in Spanish, is a national public holiday in Panama, observed on January 9th every year. This day commemorates the Martyrs of January 9, 1964, who died during riots over sovereignty of the Panama Canal Zone. These riots were triggered by a dispute between local students and Canal Zone Police officers, culminating in violence that resulted in the loss of twenty-one Panamanian citizens' lives.

On Martyr's Day, Panama pays tribute to the individuals who lost their lives fighting for sovereignty, and also to educate future generations about the historical significance of that day. Many activities take place throughout the country including parades, speeches, and remembrance ceremonies. School children often participate in reenactments of the events to understand the gravity of the sacrifices made.

Martyr's Day is not just about commemorating a tragic event, but it is also regarded as a turning point in Panama's history. The events that transpired on January 9, 1964, ignited Panamanian nationalism, leading to the eventual return of the Panama Canal Zone from US control to Panama on December 31, 1999. Thus, Martyr's Day serves as a significant reminder of Panama's journey towards complete sovereignty.