Ilhabela State Park, Protected state park in São Paulo, Brazil

Ilhabela State Park covers 27,025 hectares, about 85% of the Ilhabela archipelago in São Paulo, including all or part of twelve islands, two islets and two reefs. On São Sebastião Island the boundary follows the 200-metre contour above the São Sebastião Channel, dropping to 100 metres between Ponta das Canas and Ponta da Sela and reaching the shore around Ponta do Boi. Forest covers slopes rising to the peaks of Baepi (1,025 m), Papagaio (1,037 m) and São Sebastião (1,379 m), cut by over 250 waterfalls.

The park was established in 1977 to shield the Atlantic Forest habitat and native animal species from destruction. This decision arose from growing concern about threats to the ecosystem and the need for legal protection.

The park holds eight of Ilhabela's eighteen caiçara community nuclei. These residents fish and make handicrafts, and they celebrate traditional festivals such as the Congada de São Sebastião. The consultative council formed in 2004 includes representatives of these communities alongside public-sector and civil-society members.

The park is open daily from 9:00 to 16:30. The Trilha da Água Branca runs 2,145 metres at medium difficulty past several waterfalls; groups can arrange a guide in advance. The park covers all or part of twelve islands, two islets and two reefs, so access to most of it is by boat.

The park's mountains block moist air from the sea, producing a tropical humid climate with high rainfall, thousands of streams and over 250 waterfalls of many sizes. The 2,145-metre Trilha da Água Branca, of medium difficulty, passes through Atlantic Forest and leads to several of them.