| Election Name: | 2021 Three Rivers District Council election |
| Type: | Parliamentary |
| Party Colour: | yes |
| Previous Election: | 2019 Three Rivers District Council election |
| Previous Year: | 2019 |
| Next Election: | 2022 Three Rivers District Council election |
| Next Year: | 2022 |
| Seats For Election: | 13 of 39 seats to Three Rivers District Council |
| Majority Seats: | 20 |
| Election Date: | 6 May 2021 |
| Party1: | Liberal Democrats (UK) |
| Seats Before1: | 23 |
| Seats1: | 8 |
| Seats After1: | 23 |
| Seat Change1: | 0 |
| Popular Vote1: | 10,239 |
| Percentage1: | 38.2% |
| Party2: | Conservative Party (UK) |
| Seats Before2: | 11 |
| Seats2: | 4 |
| Seats After2: | 11 |
| Seat Change2: | 0 |
| Popular Vote2: | 10,087 |
| Percentage2: | 37.6% |
| Party3: | Labour Party (UK) |
| Seats Before3: | 3 |
| Seats3: | 1 |
| Seats After3: | 3 |
| Seat Change3: | 0 |
| Popular Vote3: | 3,379 |
| Percentage3: | 12.6% |
| Map Size: | 250px |
| Council control | |
| Posttitle: | Council control after election |
| Before Election: | Liberal Democrats |
| After Election: | Liberal Democrats |
Elections to Three Rivers District Council took place on 6 May 2021 alongside other local elections in the United Kingdom. 13 of the 39 seats were elected: the seats elected were last contested in the 2016 election. The election was originally scheduled to take place on 7 May 2020, however elections were delayed nationwide by one year due to the COVID-19 pandemic.[1]
The Liberal Democrats held control of the council.[2]