Forte de São João, also known as Forte dos Biscoitinhos and Forte do Biscoitinho, is a fort in the Azores. It is located in the São Mateus da Calheta parish, in the municipality of Angra do Heroísmo, on the island of Terceira.
Situated between the Forte Grande de São Mateus da Calheta and Forte da Igreja, it cooperated with them in the defense of the Baia de São Mateus on the southern side of the island.
Technically, it can be classified as a land battery, since it is not enclosed but has a semi-circular shape. It was equipped with one piece of artillery, protected by a barbette. The structure is of masonry construction and was without any ancillary buildings.
The structure would have been repaired in the context of the Liberal Wars, and in 1862 the Baron of Basto reported that the fort was "in good condition." By 1881, however, it had been abandoned in ruins.