Sant'Agostino, Romanesque church in Pietrasanta, Italy.

Sant'Agostino is a former Augustinian church on Pietrasanta's main square, attributed to Antonio Pardini and built in the 14th century. Its marble facade, raised on a short stair, has three large blind arches topped by a loggia of slender columns and Gothic trefoil arches carved in 1431 by Leonardo Riccomanni and his father Riccomanno. The single nave has a trussed ceiling and a floor on several levels following the slope of the ground.

The Augustinian order commissioned the church in the 14th century; it is attributed to Antonio Pardini, and a 16th-century convent and the Ospedale dei Mercanti were attached. The bell tower was added in 1780. After the Napoleonic suppression of monastic orders, church and convent passed to the comune, and the convent later housed the Scolopi school. The complex is now deconsecrated.

The church preserves floor tomb slabs and fragments of 14th- and 15th-century fresco cycles from its first building phase. The lunette of the portal holds Igor Mitoraj's bronze Annunciation, added in 2013, and the convent cloister keeps eight painted lunettes of the life of Saint Augustine by Astolfo Petrazzi.

The interior is straightforward to enter and explore, with a simple layout. The adjacent former monastery now houses a library and a sculpture sketch museum, displaying work by artists from around the world.

The bell tower dates from 1780 and holds three bells plus a small one, cast in 1904 by Raffaello Magni and sons of Lucca. They have not rung since the whole complex was deconsecrated. The cloister of the 16th-century convent keeps eight surviving lunettes of frescoes by the Sienese painter Astolfo Petrazzi showing episodes from the life of Saint Augustine.