Evenings in the historical center, things get lively around Largo do Comércio; on Fridays, young locals turn it into one massive block party. Hot spots include the stairs in front of Cafofinho da Tia Dica, and along Rua da Trapiche near the water.
Ask locals or tourist offices about what's hot, and check www.kamaleao.com/saoluis. There's a vibrant LGBT scene here.
At the Beaches
The barracas (stalls) along Ponta d’Areia, São Marcos and Calhau beaches are popular drinking spots, with the added attraction of a sea breeze and, in the evenings and especially at Calhau, live music.
São Luís is the reggae capital of Brazil, and many bars and clubs have regular reggae nights, sometimes live, sometimes just DJs and vast banks of speakers. Locals like to dance reggae in couples.