The 1934 United States Senate election in Pennsylvania was held on November 6, 1934. Incumbent Republican U.S. Senator David A. Reed sought re-election to another term, but was defeated by Democratic nominee Joseph F. Guffey.
This was the first time Democrats won a Senate seat in the state since 1881. As of 2023, this is the last time the following counties have voted Democratic in a Senate election: Adams, Blair, Bedford, Cumberland, Franklin, Juniata, and Pike.
|- |-bgcolor="#EEEEEE" | colspan="3" align="right" | Totals | align="right" | 2,942,275 | align="right" | 100.00% | align="right" |