Santa Isabel Biological Reserve (Portuguese: Reserva Biológica de Santa Isabel) is a biological reserve on the coast of the municipalities of Pacatuba and Pirambu in Sergipe, Brazil.

The coastal marine reserve, with an area of 5,547 hectares (13,710 acres), was created on 20 October 1988.

Migratory birds include the common tern (Sterna hirundo).

Tropical mockingbird (mimus gilvus) and pectoral antwren (herpsilochmus pectoralis) are endemic.

[2] The critically endangered hawksbill sea turtle (eretmochelys imbricata) is protected in the reserve.