In Portugal, Republic Day (Portuguese: Dia da República) is a national holiday celebrated on October 5th, commemorating the establishment of the First Portuguese Republic in 1910, after the constitutional monarchy was overthrown. The day is marked with various activities including ceremonial military parades, music concerts, and cultural events. The day is a symbol of national pride and offers people a chance to reflect on the country's heritage and its aspirations for the future.

Republic Day is significant as it marks the end of the monarchy, which had been in power for nearly 800 years. The monarchy was replaced by a democratic republic, which to this day, represents the Portuguese state. Portugal was one of the longest-lived monarchies in Europe, but the legitimate heir to the throne, King Manuel II, was overthrown during the 1910 revolution, which resulted in the establishment of the First Portuguese Republic.

On this day, the President of Portugal delivers a speech to signify the importance of the day and to highlight achievements and future aspiration of the country. Wreaths are laid at the tombs of the patriots and the Portuguese flag is hoisted at public and private institutions to commemorate the day. Republic day is a national holiday where family and friends get together for celebrations and it serves as a reminder of the country's evolution throughout the years, and the democratic values that it now espouses.