Agudas Achim Synagogue, formally known as Congregation Agudas Achim (transliterated from Hebrew as "Gathering of brothers"), is a Reform Jewish synagogue located on Rock Avenue in Livingston Manor, Sullivan County, New York, in the United States. The stucco-sided wooden building was erected in the 1920s to serve the growing Jewish community in that area of the Catskills. It served the large summer population of Jews from the New York City area who vacationed at family resorts in the region.
The congregation was founded in 1913 as an unofficially Orthodox group that consisted of a diverse group of local Jews, not all of whom were Orthodox. The synagogue was built two years later. It combines features of Eastern European synagogues, reflecting the national origin of its founding Ashkenazi Jews, with some elements of historic Protestant Christian churches found in the area. Some features were also adapted from other contemporary synagogues in Sullivan County.After a period of decline in the decades after World War II, following the demise of the local resort industry in the Catskills as people went further for vacations, Agudas Achim officially became a Reform congregation to attract new members. It holds services year-round. The building remains architecturally intact from the period of its construction. In 1998 it was listed on the National Register of Historic Places.
The synagogue is located a few blocks from downtown Livingston Manor on the west side of Rock Avenue, the former route of state highway NY 17. The neighborhood is a mix of residential and commercial uses.