small circular chapel erected in the courtyard of San Pietro in Montorio in Rome on the supposed site of the martyrdom of St. Peter. It was commissioned by Ferdinand and Isabella of Spain and was built in 1502 after designs made by Donato Bramante.

The design was inspired by a particular type of classical temple—and specifically by the temple of Vesta at Tivoli—built on a circular plan and surrounded by columns. Bramante added a dome (since altered) and chose the Doric order for the structure's decoration. Remarkable for its elegantly simple reinterpretation of classical forms, the Tempietto is regarded as one of the finest examples of High Renaissance architecture.