It is located in the square of São Sebastião.
This small temple dates back to the late 15th century.
Because it is a chapel invoked to São Sebastião, a saint who protects from pests, it was built on the outskirts of the city and was excluded, in the 17th century, from the 17th century fence.
In 1596, due to the invasion of the English troops of the Earl of Essex, it was badly damaged. Bishop Fernando Martins Mascarenhas was responsible for its recovery, having financed the work for this purpose.
In the second half of the 17th century it was expanded and in the 40s of the 20th century it underwent restoration work.
It is worth mentioning the Manueline side chapel, dedicated to São Roque.