This is a list of films which have placed number one at the weekend box office in the United Kingdom during 2021.
| Week | Weekend End Date | Film | Total weekend gross (Pound sterling) | Weekend openings in the Top 10 | Reference(s) |
|---|---|---|---|---|---|
| 1–20 | – | British cinemas closed and box office reporting suspended due to the COVID-19 pandemic | [1] | ||
| 21 | £4,605,673 | Nomadland (#2), Godzilla vs. Kong (#3), Spiral: From The Book Of Saw (#4), The Unholy (#5), Mortal Kombat (#6), Those Who Wish Me Dead (#7), Raya and the Last Dragon (#8), Tom & Jerry (#9), Ammonite (#10) | [2] | ||
| 22 | £2,708,455 | Cruella (#3), Demon Slayer: Mugen Train (#4) | [3] | ||
| 23 | A Quiet Place Part II | £3,567,048 | Dream Horse (#5) | [4] | |
| 24 | £1,314,938 | Nobody (#5), The Father (#6) | [5] | ||
| 25 | Hitman's Wife's Bodyguard | £1,636,128 | In the Heights (#3), Monster Hunter (#9) | [6] | |
| 26 | Fast & Furious 9 | £6,014,132 | Supernova (#8), Dogtanian and the Three Muskehounds (#9) | [7] | |
| 27 | £2,861,393 | Freaky (#6), Another Round (#9) | [8] | ||
| 28 | Black Widow | £6,889,187 | [9] | ||
| 29 | £1,801,017 | (#2), The Forever Purge (#3), (#4), (#6), Summer of Soul (#10) | [10] | ||
| 30 | £1,410,288 | Old (#4), Off the Rails (#10) | [11] | ||
| 31 | The Suicide Squad | £3,252,028 | Jungle Cruise (#2), Spirit Untamed (#6) | [12] | |
| 32 | £2,267,135 | Stillwater (#7), The Last Letter from Your Lover (#9) | [13] | ||
| 33 | Free Guy | £2,477,891 | (#2), Don't Breathe 2 (#7), The Courier (#8) | [14] | |
| 34 | £2,267,660 | (#3), Snake Eyes (#6), The Night House (#9) | [15] | ||
| 35 | £1,607,761 | Candyman (#2), Andre Rieu’s 2021 Summer Concert: Together Again (#4) | [16] | ||
| 36 | Shang-Chi and the Legend of the Ten Rings | £5,759,504 | Rise of the Footsoldier: Origins (#10) | [17] | |
| 37 | £3,583,848 | Respect (#3), Malignant (#5), Copshop (#7) | [18] | ||
| 38 | £2,362,692 | Small World (#10) | [19] | ||
| 39 | £1,558,002 | The Many Saints of Newark (#2), Oasis Knebworth 1996 (#4), The Green Knight (#8) | [20] | ||
| 40 | No Time to Die | £25,916,476 | Chal Mera Putt 3 (#6) | [21] | |
| 41 | £15,235,947 | The Addams Family 2 (#2), Deadly Cuts (#9) | [22] | ||
| 42 | £8,404,165 | (#2), Halloween Kills (#3), Ron's Gone Wrong (#5), The Last Duel (#6), Honsla Rakh (#8), Arracht (#10) | [23] | ||
| 43 | Dune | £5,876,892 | (#4), The French Dispatch (#6), Dear Evan Hansen (#9) | [24] | |
| 44 | No Time to Die | £3,514,308 | Hary Potter and the Philosopher's Stone (#6), Last Night in Soho (#8) | [25] | |
| 45 | Eternals | £5,456,577 | Spencer (#6) | [26] | |
| 46 | £2,918,586 | [27] | |||
| 47 | £4,314,263 | King Richard (#5) | [28] | ||
| 48 | House of Gucci | £2,425,628 | Encanto (#3), Anything Goes - The Musical (#7) | [29] | |
| 49 | £1,511,982 | Christmas with Andre (#4), Boxing Day (#7), (#8), Dziewczyny Z Dubaju (#10) | [30] | ||
| 50 | West Side Story | £1,297,786 | Clifford the Big Red Dog (#2), Home Alone (#7), Elf (#9), A Boy Called Christmas (#10) | [31] | |
| 51 | £31,899,232 | Pushpa: The Rise - Part 1 (#7), The Nutcracker - Bolshoi Ballet 2021 (#10) | [32] | ||
| 52 | £4,619,518 | The Matrix Resurrections (#2), 83 (#5) | [33] | ||
| 1. | No Time to Die | £97.9 | |
| 2. | Sony | £96.9[35] | |
| 3. | Dune | £21.9 | |
| 4. | Shang-Chi and the Legend of the Ten Rings | Disney | £21.9 |
| 5. | Peter Rabbit 2 | Sony | £20.5 |
| 6. | Black Widow | Disney | £18.8 |
| 7. | Sony | £18.0 | |
| 8. | Free Guy | Disney | £16.9 |
| 9. | Fast and Furious 9 | Universal | £16.5 |
| 10. | Eternals | Disney | £14.9 |
| U | Peter Rabbit 2[36] | |
| PG | The Addams Family 2[37] | |
| 12A | No Time to Die[38] | |
| 15 | [39] | |
| Halloween Kills[40] |