It encompasses much of central Connecticut and includes towns within Hartford, Litchfield, and Middlesex counties.

Principal cities include: Bristol, Hartford, and Torrington.

The district has been represented by Democrat John B. Larson since 1999.

For the 118th and successive Congresses (based on redistricting following the 2020 census), Connecticut's 1st district contains portions of four planning regions and 27 municipalities.

[3] Capitol Planning Region (17) Lower Connecticut River Valley Planning Region (3) Naugatuck Valley Planning Region (1) Northwest Hills Planning Region (6) The district has the lowest Republican voter performance of the five Connecticut house seats.