She married producer Patrick Curtis in 1966 and divorced him in 1972.In 1980, she began a 10-year marriage to André Weinfeld, whom she divorced in 1990.She first won attention for her role in Fantastic Voyage (1966), after which she won a contract with 20th Century Fox. She had only three lines in the film, yet images of her in the doe-skin bikini which she wore became best-selling posters that turned her into a celebrity sex symbol.
She was one of many women who auditioned for the role of Mary Ann Summers on the television series Gilligan's Island.
Welch's first featured role was in beach film A Swingin' Summer (1965).
But she tried very hard and went to see the rushes each day, gradually improving. Like Maria, Raquel can't act from here to there, but both ladies seem to have been born to be photographed...
this sappiest of spy pictures." Fox wanted Welch to play Jennifer in their adaptation The Valley of the Dolls but she refused, wanting to play the role of Neely.
In 1959, she played the title role in The Ramona Pageant, a yearly outdoor play at Hemet, California, which is based on the novel Ramona by Helen Hunt Jackson and Bob Biloe.