Congregation Beth Israel (Hebrew: בית ישראל) is an egalitarian Conservative synagogue and congregation located at 15 Jamesbury Drive in Worcester, Massachusetts, in the United States. Founded in 1924 as an Orthodox synagogue, the congregation formally affiliated with the United Synagogue of Conservative Judaism in 1949, and describes itself as the "leading Conservative congregation in Central Massachusetts."

The congregation first worshipped at a house on Pleasant Street; it constructed a synagogue building in its place in 1939. It completed its current location on Jamesbury Drive in 1959.

The congregation hired its first permanent rabbi, Israel Chodos, in 1940. Subsequent rabbis have included Emanuel Green (1942-1944), Sidney Guthman (1944-1948), Herbert Ribner (1948–1955), Abraham Kazis (1955–1973), Baruch Goldstein (1971–1986), and Jay Rosenbaum (1983–2003). In 1994, the synagogue and Rosenbaum were the subject of the book And They Shall be My People: An American Rabbi and His Congregation by Paul Wilkes.

Joel Pitkowsky succeeded Rosenbaum as rabbi in 2003. Pitkowsky left in 2011 and was succeeded by Rabbi Steven Schwarzman. Rabbi Schwarzman left in 2014 and was succeeded by Rabbi Aviva Fellman.

Beth Israel was founded in 1924 as an Orthodox synagogue. The congregation initially worshiped at 835 Pleasant Street, in a house that had room for up to 75 worshipers. That same year it also founded a Sunday school.

Beth Israel hired its first permanent rabbi in 1940, and constructed its first building, on Pleasant Street (replacing the existing house) in July 1939, at a cost of $75,000 (today $1,700,000). The new building's sanctuary could accommodate 500 people. After World War II the congregation grew rapidly, from 242 member families in 1945, to 451 in 1953; by then the Hebrew school had 261 children in it. In 1945 the congregation voted to become Conservative, and in 1949 formally joined the United Synagogue of America (now United Synagogue of Conservative Judaism).

Herbert Ribner served as rabbi from 1948 to 1955, and was followed by Abraham Kazis in 1955. In 1957, Beth Israel was the second largest of Worcester's eleven Jewish congregations, with 532 member families; the largest, the Reform Temple Emanuel, had 1,340 member families (42 families were members of both).

In 1953, Beth Israel purchased 12.9 acres (5.2 ha) of land on Jamesbury Drive for $42,000 (today $460,000), and began construction of their current building on it in 1958. Completed in 1959, the building cost $735,000 (today $7.9 million), of which over $300,000 (today $3.2 million) was mortgaged. The building had a main sanctuary that sat 476, a chapel with seating for 110, and a social hall that could accommodate up to 950 people. For the High Holidays, the sanctuary could be expanded into the social hall, providing seating for 1,450. The mortgage was retired in 15 years. The structure at 835 Pleasant Street was sold on September 10, 1959 to the Orthodox Shaarai Torah Synagogue, to serve as its west side branch.