His career was at its peak in the 1960s, with a series of leading roles in British science fiction films, including The Day the Earth Caught Fire (1961 - a disaster film in which he played an alcoholic reporter during a time when ever larger nuclear explosions could alter the Earth"s axis, propelling the Earth towards the sun), First Men in the Moon (1964), and Island of Terror (1966). As well as starring in these films, he worked as a soap opera actor and performed other character parts on television His roles in these classic science fiction films were highly praised by audiences and critics alike.
Judd was also famous for the 1975 "Think Once, Think Twice, Think Bike" campaign on making motorists aware of the risks faced on the road by motorcyclists.
Judd"s success in The Day the Earth Caught Fire saw Columbia Pictures sign him to a long term contract. According to Val Guest though "he was such a pain in the ass to everybody.
He had an enormous opinion of himself and he was his own worst enemy. Columbia just loaned him out here and there and then let him go."
Judd appeared regularly on television Very little is known of his life after the 1970s.
He was heard in an episode of the British Broadcasting Corporation Radio comedy Drop Maine Here, Darling, starring Leslie Phillips, in 1983, as well as playing Barrymore in a televised version of The Hound of the Baskervilles the same year, and the British Broadcasting Corporation Radio play Philadelphia Moonshine in 1985.
He appeared in the 1988 television film Jack the Ripper as Thomas Arnold. In the early 1970s, he lived in Cottenham Park Road, Wimbledon. As of 1990, he lived in the Phoenix Hotel in Wimbledon and was a cr officer for a Canadian Investment Bank.
He lived at a retirement home in Mitcham in his last years.