1828 United States House of Representatives elections in Pennsylvania

Elections to the United States House of Representatives were held in Pennsylvania on October 14, 1828, for the 21st Congress. Members of three different parties were elected to the 21st Congress, the first time in US history that a third party won seats. The new Anti-Masonic Party won a total of 5 seats, 1 of which was in Pennsylvania.

Background
In the previous election, 20 Jacksonians and 5 Anti-Jacksonians had been elected with one vacancy, which was filled in a special election by an Anti-Jacksonian, for a total of 20 Jacksonians and 6 Anti-Jacksonians.

Congressional districts
Pennsylvania was divided into 18 districts, 6 of which were plural districts
 * The PA's 1st congressional district consisted of southern Philadelphia County
 * The PA's 2nd congressional district consisted of the City of Philadelphia
 * The PA's 3rd congressional district consisted of northern Philadelphia County
 * The PA's 4th congressional district (3 seats) consisted of Chester, Delaware and Lancaster Counties
 * The PA's 5th congressional district consisted of Montgomery County
 * The PA's 6th congressional district consisted of Dauphin and Lebanon Counties
 * The PA's 7th congressional district (2 seats) consisted of Berks, Lehigh, and Schuylkill Counties
 * The PA's 8th congressional district (2 seats) consisted of Bucks, Northampton, Pike, and Wayne Counties
 * The PA's 9th congressional district (3 seats) consisted of Bradford, Columbia, Luzerne, Lycoming, McKeane, Northumberland, Potter, Susquehanna, and Tioga Counties
 * The PA's 10th congressional district consisted of York County
 * The PA's 11th congressional district (2 seats) consisted of Adams, Cumberland, Franklin, and Perry Counties
 * The PA's 12th congressional district consisted of Centre, Clearfield, Huntingdon, Mifflin, and Union Counties
 * The PA's 13th congressional district consisted of Bedford, Cambria, and Somerset Counties
 * The PA's 14th congressional district consisted of Fayette and Greene Counties
 * The PA's 15th congressional district consisted of Washington County
 * The PA's 16th congressional district (2 seats) consisted of Allegheny, Armstrong, Beaver, and Butler Counties
 * The PA's 17th congressional district consisted of Indiana, Jefferson, and Westmoreland Counties
 * The PA's 18th congressional district consisted of Crawford, Erie, Mercer, Venango, and Warren Counties

Note: Several of these counties covered larger areas than today, having since been divided into smaller counties

Election results
20 incumbents (15 Jacksonians and 5 Anti-Jacksonians) ran for re-election, of whom 12 (all Jacksonians) were re-elected. The incumbents Charles Miner (AJ) of the PA's 4th congressional district, George Kremer (J), Espy Van Horne (J), and Samuel McKean (J) of the PA's 9th congressional district, John Mitchell (J) of the PA's 12th congressional district and Robert Orr, Jr. (J) of the PA's 16th congressional district did not run for re-election.

A total of 8 seats changed parties. One seat changed from Jacksonian control to Anti-Masonic control, one changed from Jacksonian to Anti-Jacksonian, and six changed from Anti-Jacksonian to Jacksonian, for a net change of five seats lost by the Anti-Jacksonians, four gained by the Jacksonians, and one gained by the Anti-Masonics.

Special elections
Two special elections were held in 1829 for the 21st Congress. The first was held on October 13, 1829 in the PA's 8th congressional district to fill two vacancies caused by the resignations of Samuel D. Ingham (J) and George Wolf (J) before the first meeting of the 21st Congress. Wolf's resignation was due to his having been elected Governor of Pennsylvania. The second was held on December 15, 1829 in the PA's 16th congressional district, to fill a vacancy caused by the resignation of William Wilkins (AM) on November 9, 1829, before the first session of the 21st Congress began.

No seat changed parties after these special elections.