Maryland House of Delegates District 3A is one of the 67 districts that compose the Maryland House of Delegates.

Along with subdistrict 3B, it makes up the 3rd district of the Maryland Senate.

District 3A includes part of Frederick County and is represented by two delegates.

[1] As of the 2020 United States census, the district had a population of 94,029, of whom 72,483 (77.1%) were of voting age.

The racial makeup of the district was 52,465 (55.8%) White, 16,152 (17.2%) African American, 582 (0.6%) Native American, 5,324 (5.7%) Asian, 32 (0.0%) Pacific Islander, 9,044 (9.6%) from some other race, and 10,377 (11.0%) from two or more races.