| Paul Mario Day - vocal | 1975-1976 |
| Dennis Wilcock - vocal | 1976-1978 |
| Paul Di'Anno - vocal | 1978-1981 |
| Bruce Dickinson - vocal | 1981-1993, 1999- |
| Blaze Bayley - vocal | 1994-1999 |
| Terry Rance - guitar | 1975-1976 |
| Dave Sullivan - guitar | 1975-1976 |
| Bob Sawyer - guitar | 1976 |
| Dave Murray - guitar | 1976, 1977- |
| Terry Wapram - guitar | 1977 |
| Paul Cairns - guitar | 1979 |
| Paul Todd - guitar | 1979 |
| Tony Parsons - guitar | 1979 |
| Dennis Stratton - guitar | 1980 |
| Adrian Smith - guitar | 1980-1990, 1999- |
| Janick Gers - guitar | 1990- |
| Steve Harris - bass | 1975- |
| Ron "Rebel" Matthews - drums | 1975-1977 |
| Barry "Thunderstick" Purkis - drums | 1977 |
| Doug Sampson - drums | 1977-1980 |
| Clive Burr - drums | 1980-1982 |
| Michael "Nicko" McBrain - drums | 1983- |
| Tony Moore - keyboards | 1977 |
