John Joseph Slater Jr.[2] (November 25, 1925 – July 17, 1998) was an American lawyer and politician who served as mayor of Chelsea, Massachusetts, and as a member of the Massachusetts House of Representatives.

[3] During World War II he was a radio operator for the United States Navy in the Pacific theater.

[4] During the administration of mayor Kevin White, Slater served as the assistant corporation counsel for the City of Boston.

He then served as assistant counsel to the Massachusetts House of Representatives.

[13][14] Slater died on July 17, 1998, of pancreatic cancer at Massachusetts General Hospital.