Maryland's 1st congressional district encompasses the entire Eastern Shore of Maryland, including Salisbury, as well as Harford County and parts of Baltimore County; it is the largest congressional district in the state geographically, covering 11 counties (in whole or part).

The district is currently represented by Republican Andy Harris, who defeated Democratic incumbent Frank M. Kratovil Jr. in 2010.

The district was the subject of a 2014 boycott following legislation Harris introduced nullifying a District of Columbia law de-criminalizing possession of marijuana.

[3] With a Cook Partisan Voting Index rating of R+11, it is the only Republican district in Maryland.

[2] For the 118th and successive Congresses (based on redistricting following the 2020 census), the district contains all or portions of the following counties and communities:[7] Baltimore County (6) Caroline County (13) Cecil County (8) Dorchester County (14) Harford County (16) Kent County (13) Queen Anne's County (13) Somerset County (11) Talbot County (7) Wicomico County (19) Worcester County (11)