The patrons of Leffe are Saint Michael the Archangel and Saint Martin, celebrated together on 11 November, in the Church of San Michele Arcangelo and the Church of San Martino respectively.
The sacristy holds valuable works, including the canvas by Simone Brentana depicting Saint Michael's Fight against the Dragon and one by Antonio Balestra with the Madonna and Child, Saint Anthony and Saint Dominic. The town also holds the «Martinelli Ginetto» Textile Museum.