| Election Name: | 1974 United States Senate election in Ohio |
| Country: | Ohio |
| Type: | presidential |
| Ongoing: | no |
| Previous Election: | 1968 United States Senate election in Ohio |
| Previous Year: | 1968 |
| Next Election: | 1980 United States Senate election in Ohio |
| Next Year: | 1980 |
| Election Date: | November 5, 1974 |
| Image1: | File:John Glenn Portrait (3x4).jpg |
| Nominee1: | John Glenn |
| Party1: | Democratic Party (United States) |
| Popular Vote1: | 1,930,670 |
| Percentage1: | 64.62% |
| Nominee2: | Ralph Perk |
| Party2: | Republican Party (United States) |
| Popular Vote2: | 918,133 |
| Percentage2: | 30.73% |
| Map Size: | 210px |
| U.S. Senator | |
| Before Election: | Howard Metzenbaum |
| Before Party: | Democratic Party (United States) |
| After Election: | John Glenn |
| After Party: | Democratic Party (United States) |
The 1974 United States Senate election in Ohio took place on November 5, 1974. It was concurrent with elections to the United States House of Representatives. Incumbent Democratic U.S Senator Howard Metzenbaum was running for election his first full term after he was appointed in 1974 by Ohio governor John J. Gilligan to fill out the Senate term of William B. Saxbe, who had resigned to become United States Attorney General. Metzenbaum lost the primary election to John Glenn, who went on to win the general election and win every county in the state. Metzenbaum would later be elected in the other U.S. Senate seat in 1976 and worked with Glenn until he retired from the post in 1994.
The Democratic Primary that year was seen as competitive between John Glenn, a former Astronaut, and Howard Metzenbaum, the incumbent senator, a rematch in the 1970 senate race primary in Ohio.