Santissima Trinità della Missione in Prati is a 20th century convent church at Via Pompeo Magno 21 in the rione Prati east of Vatican City, and is a dependent church of San Gioacchino in Prati.
The dedication is to the Holy Trinity.
This is a convent church of the “Congregazione della Missione” or Lazarist Fathers, founded by St Vincent de Paul in 1625. The Lazarists moved here after their former convent of Santissima Trinità della Missione was sequestered in 1873. The church was built in 1920.
The convent is the headquarters of their Roman province, and from 1938 is also the home of the Collegio Ecclesiastico Leoniano for training priests of the congregation.
The church has an architectural identity, but is completely invisible from the street. This is because the convent is a four-storey structure occupying the entire city block, with four wings around a central courtyard. The church is located in the courtyard, under its own roof but joined onto the convent premises at either end.
Each nave side wall has a three-sided external chapel.
The important aspect of this otherwise low-profile church is that it contains some artworks and furnishings from the destroyed historic church of Santissima Trinità della Missione in Montecitorio.
The former sanctuary was in a narrow barrel-vaulted rectangular apse. However, the original polychrome marble altar that it contained was dismantled and the materials used in a free-standing altar erected in 1965. The large altarpiece depicting Our Lady of the Cenacle, painted for the new church by Eugenio Cisterna, was left in place.
The three paintings in the Miraculous Medal chapel also came from Montecitorio. They are by Alessandro Franchi, and depict the apparitions of Our Lady to St Catherine Labouré. The vault fresco is by Alfiovino Missori, 1953.
The St Vincent de Paul chapel was fitted out in 1925, and is a copy of a lost chapel in the old church. The altarpiece by Aureliano Milani depicts the saint at prayer. The right hand painting is by Guglielmo De Sanctis, painted in 1855 and depicting the saint at a conference of the early Lazarists. Both of these came from the old church. The left hand painting is a copy of a lost fresco in the former chapel, showing the saint assisting at the deathbed of King Louis XIII of France. The vault fresco is by Missori again, but much earlier (1927).