He was born in São Paulo, Brazil to English parents; his father was a consultant for the fishery industry in Brazil at the time. Scott-Taylor started going to drama school at age 11. He played the character of Jim Hawkins in a stage musical of Treasure Island in 1973. He went on to take minor roles in The Copter Kids (1976), Bugsy Malone (1976) and The Four Feathers (1977), after which he was chosen to play teen Damien Thorn in Damien: Omen II (1978).
In 1979, he played the role of Lucius, Brutus' servant, in a BBC production of Shakespeare's The Tragedy of Julius Caesar.