2020 Idaho Senate election should not be confused with 2020 United States Senate election in Idaho.
| Election Name: | 2020 Idaho Senate election |
| Country: | Idaho |
| Type: | legislative |
| Ongoing: | no |
| Previous Election: | 2018 Idaho Senate election |
| Previous Year: | 2018 |
| Next Election: | 2022 Idaho Senate election |
| Next Year: | 2022 |
| Seats For Election: | All 35 seats in the Idaho Senate |
| Majority Seats: | 18 |
| Leader1: | Chuck Winder |
| Party1: | Idaho Republican Party |
| Leaders Seat1: | 20th District |
| Seats Before1: | 28 |
| Seats After1: | 28 |
| Popular Vote1: | 284,487 |
| Percentage1: | 60.22% |
| Leader2: | Michelle Stennett |
| Party2: | Idaho Democratic Party |
| Leaders Seat2: | 26th district |
| Seats Before2: | 7 |
| Seats After2: | 7 |
| Popular Vote2: | 159,391 |
| Percentage2: | 33.74% |
| Map Size: | 351px |
| Majority Leader | |
| Before Election: | Chuck Winder |
| Before Party: | Idaho Republican Party |
| After Election: | Chuck Winder |
| After Party: | Idaho Republican Party |
The 2020 Idaho Senate election took place as part of the biennial 2020 United States elections. Idaho voters elected state senators in all of the state's 35 senate districts. State senators serve two-year terms in the Idaho Senate.
No seats changed hands in the election, with the closest, the Moscow-based District 5, being within one percentage point of flipping.
Six incumbents did not run for re-election in 2020. Those incumbents are:
| Party | Candidates | Votes | Seats | |||||||
|---|---|---|---|---|---|---|---|---|---|---|
| % | Before | Up | Won | After | +/– | |||||
| Republican | 34 | 284,487 | 60.22% | 28 | 28 | 28 | 28 | |||
| Democratic | 16 | 159,391 | 33.74% | 7 | 7 | 7 | 7 | |||
| Independent | 3 | 22,101 | 4.68% | 0 | 0 | 0 | 0 | |||
| Libertarian | 1 | 4,916 | 1.04% | 0 | 0 | 0 | 0 | |||
| Constitution | 1 | 1,528 | 0.32% | 0 | 0 | 0 | 0 | |||
| Total | 472,423 | 100.0% | 35 | 35 | 35 | 35 | ||||
| Source: Idaho Elections Results | ||||||||||
| District | Winner | Margin | ||
|---|---|---|---|---|
| District 5 | data-sort-value=1 | Democratic | 0.88% | |
| District 15 | data-sort-value=1 | Republican | 5.98% | |
| District 26 | data-sort-value=1 | Democratic | 12.7% |