The patron saint of Trezzano sul Naviglio is Saint Ambrose, bishop and Doctor of the Church, celebrated on 7 December in the parish church named after him, following the Ambrosian liturgical calendar observed by the diocese of Milan.
The municipal territory also holds the church of San Lorenzo, the Oratory of Sant'Apollinare and the church of Santa Gianna Beretta Molla. Among the town's places of interest is also the Parco Virgilio.
