Santa Maria in Posterula, Medieval church in Ponte district, Rome, Italy

Santa Maria in Posterula was a church located on Strada dell'Orso in Rome, equipped with a bell tower, two bells, and multiple altars for worship. The building served a parish community of around 171 families living in the surrounding residential area.

Santa Maria in Posterula is first recorded in the Liber pontificalis under Pope Nicholas I (858–867) as Sant'Agata, and appears as Sancte Marie in Pusterulis in Cencio Camerario's late-12th-century catalogue and in papal bulls of 1205 and 1222. Its parish was suppressed under Pope Leo XII in 1824, and the church was demolished at the end of the 19th century to build the Lungotevere Tor di Nona and Marzio.

The church served as a pilgrimage site for worshippers drawn to the revered image of Our Lady of Grace. This religious focus shaped community life and attracted people from across the city.

The site is no longer accessible today as the church was demolished in 1895. The nearby Ponte Umberto I now stands where it once was, marking Rome's urban transformation over the centuries.

In 1819 the church and its monastery were granted to Irish Augustinians, who moved here from San Matteo on Via Merulana with a venerated 14th-century icon of Our Lady of Perpetual Help. In 1866 that icon was transferred to Sant'Alfonso all'Esquilino, and after the demolition the Madonna delle Grazie image went to San Patrizio a Villa Ludogusi.