Congregation Shaar Hashomayim, Ashkenazi synagogue in Westmount, Montreal, Canada

Congregation Shaar Hashomayim is an Ashkenazi synagogue on Kensington Avenue in Westmount, dedicated in 1922, with a cornerstone laid by president Lyon Cohen in 1921. Its sanctuary follows Moorish Revival architecture. The congregation, incorporated in 1846, is the oldest Ashkenazi synagogue in Canada and the largest traditional synagogue in the country.

Founded in 1846 by English, German and Polish Jews who had attended the Spanish and Portuguese Synagogue, the congregation first rented space on Saint James Street. Its first synagogue was built on Saint Constant Street in 1859, followed by one on McGill College Avenue in 1885–1886 costing $40,000. Land on Kensington Avenue was bought in 1920; president Lyon Cohen laid the cornerstone in 1921 and the synagogue was dedicated on 17 September 1922.

The congregation keeps the choral tradition of European synagogues, with an all-male choir established in 1887 and a hazzan leading every Shabbat and holiday service. Early by-laws prescribed the practices of London's Great Synagogue. Clergy wear robes, and the president and officers seated on the bimah wear top hats.

Men generally wear business attire and women cover their shoulders at services; clergy and officers wear morning suits, with top hats on the bimah and tailcoats on Festivals. Services are led every Shabbat and on Jewish holidays by a hazzan with an all-male choir. The building stands on Kensington Avenue in Westmount.

The choir sang backing vocals on Leonard Cohen's "You Want It Darker" and on "It Seemed the Better Way", with Cantor Gideon Zelermyer. In 2017 members performed the title track and "Tower of Song" at the Montreal tribute concert alongside Willie Nelson, Céline Dion, Peter Gabriel and Chris Martin, and later appeared on "Puppets" from Thanks for the Dance.