Congregation B'nai Israel is a Reform Jewish congregation and synagogue, located at 3600 Riverside Boulevard, in Sacramento, California, in the United States. Founded in 1852 as an Orthodox community, the congregation is the oldest Jewish congregation in Sacramento. The congregation dates the California Gold Rush of 1849, when Jewish settlers gathered to observe the High Holy days. The congregation purchased its first building at 7th and L streets on September 2, 1852, making it the first synagogue west of the Mississippi River.