Using her résumé from modelling, her mother got her an agent and Tuesday (an extension of her childhood nickname, "Tu-Tu") Weld made her acting debut on television at age 12 and her motion picture debut at the age of 13 in a bit role in the 1956 Alfred Hitchcock crime drama, The Wrong Man. That same year, Weld got the lead in a film celebrating the advent of Rock and Roll called Rock, Rock, Rock that featured record promoter Alan Freed and singers Chuck Berry, Frankie Lymon, and Johnny Burnette. In the film, Connie Francis did the vocals for Weld's singing parts. In 1959, still only sixteen years old, she was given a role in the CBS television show, The Many Loves of Dobie Gillis. Although Weld was a cast member for only a single season, the show gave her considerable national publicity, and she was named a co-winner of a "Most Promising Newcomer" award at the Golden Globe Awards.

Despite talent, beauty, and early success Tuesday Weld was frequently described as a poster-girl for self-destruction. The product of a dysfunctional family, she claims to have suffered a nervous breakdown at the age of nine. With no parental guidance from a mother with whom she would have a lifelong strained relationship, by age ten she had begun smoking and drinking. In her early teens she lost her virginity in a hapless relationship that, combined with her other problems, led to a suicide attempt. The teenage Weld dated a series of much older men, and was known for going barefoot and being shocking and abrasive in public.

In 1961, after starring opposite Elvis Presley in Wild in the Country, the two began an off-screen romance. However, in Hollywood, her reputation for a recklessness was fodder for the gossip columnists and Louella Parsons reportedly said, drily, "Miss Weld is not a very good representative for the motion picture industry."

Tuesday Weld appeared with Jackie Gleason and Steve McQueen in the 1963 comedy/drama, Soldier in the Rain, and although her performance was well received, the film was only a minor success. Although frequently typecast as the "blonde in the tight sweater," critics and others in the film industry have acknowledged her talent. However, Weld never achieved the level of stardom many thought her looks and abilities would bring, partly as a result of her turning down roles in films that became great successes and that made mega-stars out of others, such as Lolita, Bonnie and Clyde, True Grit, and Bob & Carol & Ted & Alice. Actor Roddy McDowall, who co-starred with her in a 1966 film, said: "no actress was ever so good in so many bad films."

Weld married screenwriter Claude Harz in 1965 and gave birth to a daughter, Natasha, in 1966. The same year she appeared in the successful Norman Jewison film, The Cincinnati Kid, opposite Steve McQueen. Some of her most notable screen performances include "Pretty Poison" (1968), co-starring Anthony Perkins, "Walk the Line" (1971), opposite Gregory Peck, and "Play it as it Lays" (1972) for which she was nominated for a Golden Globe Award.

In her thirties, Weld gave memorable performances in "Looking for Mr. Goodbar" (1977), for which she was nominated for an Academy Award as best supporting actress, 1978's "Who'll Stop the Rain" opposite Nick Nolte and Michael Mann's acclaimed 1981 film "Thief", opposite James Caan. Weld has also appeared in a number of made-for-television movies, including "Reflections of Murder" (1987) and "A Question of Guilt", in which she played a woman accused of murdering her children.

After divorcing her first husband, Weld married famed British comedian/actor Dudley Moore, in 1975. In 1976 they had a son, Patrick, and in 1980 after a number of separations, were finally divorced. Weld married the renowned Israeli concert violinist and conductor Pinchas Zukerman in 1985. After thirteen years, that marriage also ended in divorce.

Weld's photograph was featured on the covers of two Matthew Sweet albums, his 1991 "Girlfriend" and 2000 "Time Capsule: The Best of Matthew Sweet."

Tuesday Weld continues to makes occasional appearances in film and television.