Located in the western part of the state and spanning across parts of Fairfield, Litchfield, New Haven, and Hartford Counties, the district runs from Meriden and New Britain in central Connecticut, westward to Danbury and the surrounding Housatonic Valley, encompassing the Farmington Valley, Upper Naugatuck River Valley, and the Litchfield Hills.

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] In the early 20th century, the 5th congressional district included Waterbury, Litchfield County, and the Naugatuck Valley.

The current 5th congressional district was created in 2002 due to reapportionment following the 2000 U.S. census.

For the 118th and successive Congresses (based on redistricting following the 2020 census), Connecticut's 5th district contains portions of four planning regions and 40 municipalities.