| Title | Weekend | Week | Total | % Change | Total Weeks |
| 1 (new) |  | There's Something About Mary (1998) | £2,076,411 | £2,076,411 | £2,076,411 | new | 1 |
| 2 (1) |  | Saving Private Ryan (1998) | £1,695,902 | £3,028,962 | £9,760,779 | -18% | 3 |
| 3 (2) |  | Lethal Weapon 4 (1998) | £1,185,107 | £2,025,912 | £4,075,518 | -42% | 2 |
| 4 (3) |  | Lock, Stock & Two Smoking Barrels (1998) | £659,486 | £1,107,462 | £7,198,005 | -7% | 5 |
| 5 (6) |  | Doctor Dolittle (1998) | £343,274 | £430,890 | £18,409,950 | 7% | 9 |
| 6 (5) |  | Armageddon (1998) | £238,958 | £372,879 | £15,978,907 | -25% | 8 |
| 7 (4) |  | The Horse Whisperer (1998) | £214,800 | £482,565 | £4,982,956 | -34% | 5 |
| 8 (14) |  | The Land Girls (1998) | £129,088 | £157,681 | £407,035 | 79% | 4 |
| 9 (7) |  | The X Files (1998) | £108,426 | £215,143 | £8,280,945 | -48% | 6 |
| 10 (new) | | Dancing At Lughnasa (1998) | £97,077 | £97,077 | £97,077 | new | 1 |
| 11 (8) |  | Lost In Space (1998) | £53,948 | £71,615 | £10,573,626 | -22% | 9 |
| 12 (9) |  | The Last Days of Disco (1998) | £43,200 | £74,661 | £388,903 | -14% | 4 |
| 13 (10) |  | Godzilla (1998) | £42,005 | £48,623 | £15,879,821 | -15% | 11 |
| 14 (11) |  | Love Is the Devil: Study For a Portrait of Francis Bacon (1998) | £38,322 | £70,795 | £116,872 | -17% | 2 |
| 15 (13) |  | The Spanish Prisoner (1998) | £35,228 | £54,634 | £417,040 | 13% | 5 |