Praça da República, Central square in República District, São Paulo, Brazil

Praça da República is a square in São Paulo's historic centre, bounded by Rua Pedro Américo, Rua Vinte e Quatro de Maio, Avenida Ipiranga and Avenida São João. Its largest building is the 1894 Casa Caetano de Campos, home of the State Education Department since 1979. Around it stand 1930s modernist apartment blocks: the Esther, São Tomás, Oscar Niemeyer's Eiffel and Jacques Pilon's São Luiz, the last with an air-raid shelter later used as a garage.

The square was originally called Largo dos Curros in the 19th century and served as a simple field. After 1889, it developed into a modern center with new structures and urban activity.

The square's name changed repeatedly: Largo dos Curros, Largo da Palha, Praça das Milícias, Largo Sete de Abril and Praça 15 de Novembro before 1889. Since the late 1960s it has hosted a hippie-founded crafts fair, now held on Sundays with over six hundred stalls selling art, clothing, jewellery and food from northern and northeastern Brazil and neighbouring countries.

The República metro station at the southern end connects Lines 3 and 4, providing direct access to the square from different city areas. Visitors can reach the plaza easily and explore it on foot.

The Sunday fair began in November 1956, when stamp collector J. L. Barros Pimentel started a philatelic market on the square; it later became a hippie craft fair and today fills more than six hundred stalls. Mayor José Serra tried to shut it down in 2005–2006, but it continues.