John Crawford Crosby (June 15, 1859 – October 14, 1943) was an American politician from the U.S. state of Massachusetts.

He began his political career as a member of the school committee of Pittsfield from 1884 to 1890.

Crosby served as the director of a bank and later of fire and life insurance companies.

He was elected Mayor of Pittsfield, serving from 1894 to 1895, and was a delegate to the 1896 Democratic National Convention.

Crosby was city solicitor from 1896 to 1900 and appointed a justice of the superior court on January 25, 1905, serving until December 31, 1913, when he was appointed justice of the Massachusetts Supreme Judicial Court.