| Election Name: | 2021 Colchester Borough Council election |
| Country: | Essex |
| Type: | parliamentary |
| Previous Election: | 2019 Colchester Borough Council election |
| Previous Year: | 2019 |
| Election Date: | 6 May 2021 |
| Next Election: | 2022 Colchester Borough Council election |
| Next Year: | 2022 |
| Seats For Election: | 19 out of 51 seats to Colchester Borough Council |
| Majority Seats: | 26 |
| Turnout: | 33.9% (1.3%) |
| Leader1: | Paul Dundas |
| Party1: | Conservative Party (UK) |
| Leaders Seat1: | Stanway |
| Last Election1: | 23 seats, 35.2% |
| Seats Before1: | 23 |
| Seats1: | 9 |
| Seats After1: | 23 |
| Popular Vote1: | 23,413 |
| Percentage1: | 44.8% |
| Swing1: | 9.9% |
| Leader2: | Martin Goss |
| Party2: | Liberal Democrats (UK) |
| Leaders Seat2: | Mile End |
| Last Election2: | 13 seats, 26.6% |
| Seats Before2: | 13 |
| Seats2: | 4 |
| Seats After2: | 12 |
| Seat Change2: | 1 |
| Popular Vote2: | 10,264 |
| Percentage2: | 19.7% |
| Swing2: | 6.9% |
| Leader3: | Tina Bourne |
| Party3: | Labour Party (UK) |
| Leaders Seat3: | Greenstead |
| Last Election3: | 11 seats, 17.7% |
| Seats Before3: | 11 |
| Seats3: | 4 |
| Seats After3: | 11 |
| Popular Vote3: | 11,763 |
| Percentage3: | 22.5% |
| Swing3: | 4.8% |
| Leader4: | Beverley Oxford |
| Party4: | Independent politician |
| Leaders Seat4: | Highwoods |
| Last Election4: | 3 seats, 6.3% |
| Seats Before4: | 3 |
| Seats4: | 1 |
| Seats After4: | 3 |
| Popular Vote4: | 912 |
| Percentage4: | 1.7% |
| Swing4: | 4.6% |
| Leader5: | Mark Goacher |
| Party5: | Green Party of England and Wales |
| Leaders Seat5: | Castle |
| Last Election5: | 1 seat, 13.6% |
| Seats Before5: | 1 |
| Seats5: | 1 |
| Seats After5: | 2 |
| Seat Change5: | 1 |
| Popular Vote5: | 5,592 |
| Percentage5: | 10.7% |
| Swing5: | 2.9% |
Elections to Colchester Borough Council were held on 6 May 2021. They were originally planned for 7 May 2020,[1] but postponed until 2021 due to the COVID-19 pandemic.[2] Seventeen members of the council (one-third of the whole) were up for election, one from each of the 17 wards. There were also two additional by-elections in Prettygate and Lexden & Braiswick wards, bringing the total number of elected members to nineteen.
The Statement of Nominated Persons was released on 8 April 2021 detailing the persons standing as candidates at the Borough Council election.[3]
Incumbent councillors are marked with an asterisk*
No Independent candidate as previous (-11.2).
No Independent (-28.6, -13.5) or UKIP (-7.3) candidates as previous.