About Us

Established in 1692, the Middlesex Sheriff’s Office (MSO) is one of the oldest law enforcement agencies in the United States.  Entrusted with full law enforcement capabilities, the MSO provides care, custody and control of both sentenced and pre-trial detainees.  These functions are carried out at the Middlesex Jail & House of Correction in Billerica. 

Dedication to public safety does not stop at the walls of the institution, however.  The MSO makes available to the 54 cities and towns of Middlesex County any and all resources that may enhance public safety.  We have forged partnerships with local, state and federal authorities to organize and ensure these resources are available whenever and wherever needed.

Additionally, the MSO operates a Training Academy in Chelmsford, administrative offices in Medford and a Civil Process Division office in Medford.