UK Box Office 21st April, 1978
| Title | Weekend | Week | Total | % Change | Total Weeks | ||
| 1 (2) |  | Star Wars (1977) | £505,690 | £682,682 | £15,361,671 | -18% | 17 |
| 2 (1) |  | The Stud (1978) | £273,709 | £369,507 | £1,026,409 | -58% | 2 |
| 3 (3) |  | Pete's Dragon (1978) | £205,218 | £266,783 | £595,131 | -37% | 2 |
| 4 (4) |  | Close Encounters of the Third Kind (1978) | £159,592 | £223,429 | £12,385,879 | -23% | 6 |
| 5 (5) |  | Saturday Night Fever (1978) | £85,640 | £124,178 | £3,099,611 | -55% | 5 |