The Synagogue of Casale Monferrato, which was built in 1595, is particularly known for its exquisite Baroque interior with walls and ceiling embellished with elaborate painting, carving and gilding. It is located in Vicolo Salmone Olper, an alleyway in the traditionally Jewish quarter of Casale Monferrato, which in the eighteenth century became the city’s ghetto. The plain building houses a clandestine synagogue, giving no indication of its purpose as a Jewish house of worship.
As in most early modern European synagogues, the synagogue was entered not directly from the street, but via a courtyard: both for reasons of security and to comply with laws requiring that the sound of Jewish worship not be audible by Christians.
Casale Monferrato is one of the few synagogues that survive in Piedmont, which once had many.  Others in, or close to, Monferrato and the Langhe include the Biella Synagogue, the Vercelli Synagogue, and those of Asti, Alessandria, Vercelli, Chieri, Carmagnola, Cherasco, Moncalvo and Trino Vercellese.
The synagogue is listed as a National Monument of Italy.