Labor Day, also known as May Day, is an important public holiday in Portugal, which is celebrated on the 1st of May every year. This observance is common in various parts of the globe with the aim of honouring the contributions and achievements of workers. It is a day for workers to stand up for their rights and to celebrate the progress they have achieved in terms of labour rights and conditions.

The history of Labor Day in Portugal dates back to the late 19th and early 20th centuries. This was a time of industrial revolution when workers campaigned for better working conditions, fewer working hours, and the right to form unions. In Portugal, this day became particularly important during the dictator Salazar’s regime. The Carnation Revolution, which occurred on April 25, 1974, played a major role in the celebration of Labor Day in Portugal as it marked the return of democracy and the civil liberties such as the right to strike.

On Labor Day, various events and activities are organized across Portugal. Rallies, concerts, and parades are held in the major cities, and labor unions often organize their own events. People in today's Portugal see it as a time to relax, enjoy a day off work, and spend time with their families. Despite its political origins, the day has gradually evolved into a nationally recognized day of leisure and recreation. Yet, it still serves as a reminder of the social and economic achievements of the working class.