Connecticut's 2nd congressional district is a congressional district in the U.S. state of Connecticut. Located in the eastern part of the state, the district includes all of New London County, Tolland County, and Windham County, along with parts of Hartford, Middlesex, and New Haven counties. Principal cities include Enfield, Norwich, New London, and Groton.

The district is currently represented by Democrat Joe Courtney. With a Cook Partisan Voting Index rating of D+3, it is one of the least Democratic districts in Connecticut, a state with an all-Democratic congressional delegation.^[2]

The district includes the following towns:

• Hartford County – Enfield, Glastonbury (part), Marlborough, and Suffield.
• Middlesex County – Chester, Clinton, Deep River, East Haddam, East Hampton, Essex, Haddam, Killingworth, Old Saybrook, and Westbrook.
• New Haven County – Madison.
• New London County – Bozrah, Colchester, East Lyme, Franklin, Griswold, Groton, Lebanon, Ledyard, Lisbon, Lyme, Montville, New London, North Stonington, Norwich, Old Lyme, Preston, Salem, Sprague, Stonington, Voluntown, and Waterford.
• Tolland County – Andover, Bolton, Columbia, Coventry, Ellington, Hebron, Mansfield, Somers, Stafford, Tolland, Union, Vernon, and Willington.
• Windham County – Ashford, Brooklyn, Canterbury, Chaplin, Eastford, Hampton, Killingly, Plainfield, Pomfret, Putnam, Scotland, Sterling, Thompson, Windham, and Woodstock.

District organized from Connecticut's at-large congressional district in 1837.