Santissima Trinità, Baroque church in central Turin, Italy

Santissima Trinità is a baroque church in central Turin built with a circular floor plan featuring three entrances, altars, and choirs arranged symmetrically around the interior. The central dome rises prominently above the round structure, creating a unified visual space.

The Confraternita della Santissima Trinità, founded in 1557 to assist pilgrims, demolished the 12th-century church of Sant'Agnese on via Dora Grossa in 1583 to build its own seat, designed by ducal architect Ascanio Vitozzi, who is buried there. The church was consecrated in 1606, though the dome was only finished in 1661. The western side was fitted into the new layout of via Garibaldi in the 18th century, and Angelo Marchini completed the neoclassical facade in 1830.

The steep entrance staircase faces the street and draws visitors into a space designed for formal religious gatherings and community processions. Inside, the three separate choirs created distinct areas where different groups could participate simultaneously in worship.

The church stands at the corner of Via Garibaldi and Via XX Settembre, on the stretch of Via Garibaldi that was formerly Via Dora Grossa. The entrance is on the street level of the historic centre, within walking distance of Piazza Castello and the cathedral. As an active place of worship, access may be limited during services.

The dome was never finished on the outside; Giuseppe Leoni restored it in 1846. Inside, Luigi Vacca and Francesco Gonin painted the Gloria della Santissima Trinità in Paradiso, with God the Father, Christ and the Holy Spirit dove at the centre, ringed by three hierarchies of seraphim, cherubim and thrones.