| Election Name: | 2021 Blackburn with Darwen Borough Council election |
| Country: | Lancashire |
| Type: | parliamentary |
| Ongoing: | no |
| Previous Election: | 2019 Blackburn with Darwen Borough Council election |
| Previous Year: | 2019 |
| Next Election: | 2022 Blackburn with Darwen Borough Council election |
| Next Year: | 2022 |
| Seats For Election: | 17 of the 51 seats (one third) to Blackburn with Darwen Borough Council |
| Majority Seats: | 26 |
| Image1: | Lab |
| Party1: | Labour Party (UK) |
| Seats Before1: | 35 |
| Seats1: | 11 |
| Seats After1: | 35 |
| Popular Vote1: | 18,326 |
| Percentage1: | 55.4% |
| Party2: | Conservative Party (UK) |
| Seats Before2: | 13 |
| Seats2: | 6 |
| Seat Change2: | 1 |
| Seats After2: | 14 |
| Popular Vote2: | 12,854 |
| Percentage2: | 38.8% |
| Image3: | LD |
| Party3: | Liberal Democrats (UK) |
| Seats Before3: | 1 |
| Seats3: | 0 |
| Seat Change3: | 1 |
| Seats After3: | 0 |
| Popular Vote3: | 1,654 |
| Percentage3: | 5.0% |
| Image4: | Ind |
| Party4: | Independent |
| Seats Before4: | 1 |
| Seats4: | 0 |
| Seats After4: | 1 |
| Popular Vote4: | 260 |
| Percentage4: | 0.8% |
| Council control | |
| Posttitle: | Council control after election |
| Before Election: | Labour |
| After Election: | Labour |
The 2021 Blackburn with Darwen Borough Council election took place on 6 May 2021 to elect members of Blackburn with Darwen Borough Council in England. This was on the same day as other local elections.[1] One-third of the seats were up for election.
Prior to the election, the composition of the council was:
| 35 | 13 | 1 | 1 | |
| Labour | Conservative | LD | Ind |
After the election, the composition of the council was:
| 35 | 14 | 1 | |
| Labour | Conservative | Ind |