Senator John J. Cronin was elected to the Senate in 2020 and represents the communities of Fitchburg, Leominster, Gardner, Berlin, Bolton, Lancaster, Lunenburg, Sterling, Townsend, Westminster and Clinton (precincts 1 and 2), which make up the Worcester-Middlesex District.

Senator Cronin's legislation aims to achieve mental health parity in the Commonwealth; to increase social mobility through equitable access to workforce development; and to promote the revitalization of Gateway Cities. Senator Cronin serves as Chair of the Joint Committee of Municipalities and Regional Government and as Vice Chair of Tourism, Arts, and Cultural Development.

Senator Cronin is a graduate of West Point, a former U.S. Army Infantry Officer, and a combat veteran with multiple deployments to Afghanistan. Prior to his election to the Senate, he served as a veteran advocate at the Legal Services Center of Harvard Law School.