The Social Democratic Party of Brazil (Portuguese: Partido da Social Democracia Brasileira) is a Brazilian political party. In the Brazilian National Congress it is the fourth largest party, with 71 out of 513 deputies, and 11 out of 81 senators after the 2002 general elections.

In the presidential elections held at the same time, its candidate, José Serra came second in the first round. In the run-off he lost, with 38.7% of the votes, to Luiz Inácio Lula da Silva.