Maryland House of Delegates District 34B is one of the 67 districts that compose the Maryland House of Delegates.

Along with subdistrict 34A, it makes up the 34th district of the Maryland Senate.

District 34B includes part of Harford County, and is represented by one delegate.

[1] As of the 2020 United States census, the district had a population of 44,265, of whom 34,400 (77.7%) were of voting age.

The racial makeup of the district was 34,543 (78.0%) White, 3,718 (8.4%) African American, 81 (0.2%) Native American, 1,939 (4.4%) Asian, 22 (0.0%) Pacific Islander, 866 (2.0%) from some other race, and 3,101 (7.0%) from two or more races.