He began his career at the age of six, as Annie Oakley's kid brother in Annie Get Your Gun. In 1950 Elia Kazan cast him as the son of Richard Widmark and Barbara Bel Geddes in Panic in the Streets; 20th Century-Fox signed him to a contract. He was put into The Jackpot, in which he and Natalie Wood had James Stewart and Barbara Hale for parents.
Movies were awash with youngsters, and the industry had realised that the public preferred the natural to the cute. When Fox wasn't using Rettig he was loaned out - for instance, to Universal to play Patricia Neale's offspring in Weekend with Father (1951) and to Warner Bros to be Jane Wyman's son in So Big (1953).
His most important role was in the bizarre The 5,000 Fingers of Dr T (1953), as a boy forced to stay indoors to practise piano; he imagines himself into a horrific new land lorded over by Dr Terwilliker (Hans Conreid), whose fortress contains 500 boys playing scales and, in the dungeons, moulding creatures who had dared play other instruments. His best remembered movie role is as Robert Mitchum's son in River of No Return (1954), fording the rapids with Marilyn Monroe.
In his six years in pictures Rettig had leading roles in 14 films. In 1954 he began a weekly television series with Lassie. He played Jeff Miller, the collie's master, till 1958. When show-business lost interest he tried various jobs, including photography and selling tools.
He and his wife moved to a California farm, where he cultivated marijuana; he was sentenced to two years' probation in 1972, but in 1975 was ordered to serve five years for running cocaine. That was dropped on appeal, but he was indicted again in 1980 for drug offences. Later he was a computer programmer and drug-counsellor.
Thomas Noel Rettig, actor: born Jackson Heights, New York 10 December 1941; died Marina del Rey 15 February 1996.