Massachusetts Senate's 3rd Middlesex district in the United States is one of 40 legislative districts of the Massachusetts Senate. It covers portions of Middlesex county. Democrat Mike Barrett of Lexington has represented the district since 2013. Locales represented The district includes the following localities: Bedford Carlisle Chelmsford Concord Lexington Lincoln Sudbury Waltham Weston Former locales The district previously covered the following: Brighton, circa 1860s Cambridge, circa 1860s Senators John W. Bacon, circa 1859 Elmer Stevens Joseph Knox Charles Austin Charles V. Blanchard, circa 1911 James Conlan Scanlan, circa 1935 Burton F. Faulkner, circa 1945 James J. Corbett, circa 1957 Denis L. McKenna, circa 1969 Stephen John McGrail, circa 1975 John A. Brennan, Jr., circa 1979-1985 Richard R. Tisei, circa 1993 Susan Fargo, circa 2002 Michael J. Barrett, 2013-current Images Portraits of legislators See also List of Massachusetts Senate elections List of Massachusetts General Courts List of former districts of the Massachusetts Senate Other Middlesex County districts of the Massachusett Senate: 1st, 2nd, 4th, 5th; 1st Essex and Middlesex; 2nd Essex and Middlesex; 1st Middlesex and Norfolk, 2nd Middlesex and Norfolk; Middlesex and Suffolk; Middlesex and Worcester; Norfolk, Bristol and Middlesex; 1st Suffolk and Middlesex; 2nd Suffolk and Middlesex Middlesex County districts of the Massachusetts House of Representatives: 1st, 2nd, 3rd, 4th, 5th, 6th, 7th, 8th, 9th, 10th, 11th, 12th, 13th, 14th, 15th, 16th, 17th, 18th, 19th, 20th, 21st, 22nd, 23rd, 24th, 25th, 26th, 27th, 28th, 29th, 30th, 31st, 32nd, 33rd, 34th, 35th, 36th, 37th References External links Ballotpedia (State Senate district information based on U.S. Census Bureau's American Community Survey). League of Women Voters of Sudbury Senate Government of Middlesex County, Massachusetts Massachusetts Senate