Mantua Cathedral (Italian: Cattedrale di San Pietro apostolo; Duomo di Mantova) is a Roman Catholic cathedral dedicated to Saint Peter. It is the seat of the Bishop of Mantua.

An initial structure probably existed on the site in the Early Christian era, which was followed by a building destroyed by a fire in 894. The current church was rebuilt in 1395–1401 with the addition of side chapels and a magnificent Gothic west front, which can still be seen in a sketch by Domenico Morone (preserved in the Palazzo Ducale of Mantua). The belltower has seven bells tuned in the scale of Bb.

After another fire in the 16th century, Giulio Romano rebuilt the interior but saved the frontage, which was replaced however in 1756–61 by the current Baroque one in Carrara marble. Notable characteristics of the Renaissance structure are the cusps, decorated with rose windows on the south side, which end at the Gothic bell tower.

The Trinity with the Virgin, Saint John and angels by Antonio Maria Viani (fresco in apse), Saint Margaret (1552) by Domenico Brusasorci (canvas in Chapel of the Sacrament), Saint Martin dividing his cloak with the beggar (1552) by Paolo Farinati, Glory of Saint Joseph (1616) by Niccolò Ricciolini, Saint Dominic by Bernardino Malpizzi, Madonna dell'Itria by Antonio Maria Viani, Saint Aloysius Gonzaga by Ippolito AndreasiLudovico I Gonzaga, Ludovico III Gonzaga, Marquis of Mantua.