| Election Name: | 1934 United States Senate election in Pennsylvania |
| Country: | Pennsylvania |
| Type: | presidential |
| Ongoing: | no |
| Previous Election: | 1928 United States Senate election in Pennsylvania |
| Previous Year: | 1928 |
| Next Election: | 1940 United States Senate election in Pennsylvania |
| Next Year: | 1940 |
| Election Date: | November 6, 1934 |
| Image1: | Joseph Guffey.jpg |
| Nominee1: | Joseph F. Guffey |
| Party1: | Democratic Party (US) |
| Popular Vote1: | 1,494,010 |
| Percentage1: | 50.78% |
| Nominee2: | David A. Reed |
| Party2: | Republican Party (US) |
| Popular Vote2: | 1,366,872 |
| Percentage2: | 46.46% |
| Map Size: | 240px |
| U.S. Senator | |
| Before Election: | David A. Reed |
| Before Party: | Republican Party (US) |
| After Election: | Joseph F. Guffey |
| After Party: | Democratic Party (US) |
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" | |}