Ilhabela is an archipelago and city situated in the Atlantic Ocean six kilometres off the coast of São Paulo state in Brazil. The city is 205 km (127 mi) from the city of São Paulo and 340 km (210 mi) from the city of Rio de Janeiro. The largest island, although commonly called Ilhabela, is officially named Ilha de São Sebastião. It, the other islands and the islets make up the municipality of Ilhabela.

The Ilhabela State Park is a state park in the state of São Paulo, Brazil. It protects an area of Atlantic Forest on an archipelago in the South Atlantic off the northeast coast of the state, including most of the mountainous island of São Sebastião.