| Election Name: | 1998 United States Senate election in Idaho |
| Country: | Idaho |
| Type: | presidential |
| Ongoing: | no |
| Previous Election: | 1992 United States Senate election in Idaho |
| Previous Year: | 1992 |
| Next Election: | 2004 United States Senate election in Idaho |
| Next Year: | 2004 |
| Election Date: | November 3, 1998 |
| Image1: | Mike Crapo official photo.jpg |
| Nominee1: | Mike Crapo |
| Party1: | Republican Party (United States) |
| Popular Vote1: | 262,966 |
| Percentage1: | 69.54% |
| Nominee2: | Bill Mauk |
| Party2: | Democratic Party (United States) |
| Popular Vote2: | 107,375 |
| Percentage2: | 28.39% |
| Map Size: | 250px |
| U.S. Senator | |
| Before Election: | Dirk Kempthorne |
| Before Party: | Republican Party (United States) |
| After Election: | Mike Crapo |
| After Party: | Republican Party (United States) |
The 1998 United States Senate election in Idaho was held November 3, 1998 alongside other elections to the United States Senate in other states as well as elections to the United States House of Representatives and various state and local elections. Incumbent Republican U.S. Senator Dirk Kempthorne decided to retire after one term to run for governor. Republican nominee Mike Crapo won the open seat.