Tingwell was Australia's youngest radio announcer when in school in Sydney, and during World War II served in the Royal Air Force (Britain). His first movie was an uncredited role in the 1946 movie Smithy, about pioneer aviator Charles Kingsford Smith.
He spent a short while in Hollywood, then lived in London from 1956 to 1972, before returning to Australia. Other roles included guest appearances in Thunderbirds, The Avengers, and Z Cars, and then in 1973 he began a five-year stint as Inspector Reg Lawson in the Australian police television series Homicide.
Productions for which Tingwell is well known include the movies The Castle (1997) and Breaker Morant (1980) and television series Homicide (1973—1977) and All the Rivers Run (1983).