| Title | Weekend | Week | Total | % Change | Total Weeks |
| 1 (new) |  | The Ugly Truth () | £1,976,043 | £1,976,043 | £1,976,043 | new | 1 |
| 2 (new) |  | G.I. Joe: The Rise of Cobra () | £1,708,760 | £1,708,760 | £1,708,760 | new | 1 |
| 3 (1) |  | Harry Potter and the Half Blood Prince () | £1,349,113 | £3,839,238 | £44,376,816 | -54% | 4 |
| 4 (2) |  | G Force (2009) | £1,223,891 | £3,792,806 | £6,271,330 | -51% | 2 |
| 5 (4) |  | The Proposal () | £755,242 | £2,169,905 | £9,056,654 | -49% | 3 |
| 6 (3) |  | The Taking of Pelham 123 () | £661,334 | £1,667,453 | £3,452,172 | -63% | 2 |
| 7 (5) |  | Ice Age: Dawn of the Dinosaurs () | £612,570 | £1,869,413 | £31,024,152 | -46% | 6 |
| 8 (new) |  | Orphan () | £570,146 | £570,146 | £570,146 | new | 1 |
| 9 (8) |  | The Hangover (2009) | £279,531 | £656,877 | £21,260,366 | -46% | 9 |
| 10 (9) | | Coco Before Chanel (2009) | £249,732 | £634,344 | £1,057,612 | -41% | 2 |
| 11 (7) |  | Brüno (2009) | £203,853 | £639,755 | £15,369,471 | -67% | 5 |
| 12 (6) |  | Land of the Lost () | £186,567 | £767,445 | £1,409,998 | -71% | 2 |
| 13 (10) |  | Love Aaj Kal (2009) | £161,493 | £377,421 | £783,094 | -60% | 2 |
| 14 (new) |  | Mesrine Part 1: Killer Instinct () | £135,999 | £135,999 | £135,999 | new | 1 |
| 15 (12) |  | Moon (2009) | £77,075 | £180,376 | £880,770 | -35% | 4 |