She was born in Epsom, Surrey and became a star of radio and film before reaching her early teens. She made her radio debut during World War II while attending a London radio broadcast with her father in October 1942. During an air raid, the producer requested that someone perform to settle the jittery audience, and Clark volunteered a rendition of "Mighty Lak a Rose" to an enthusiastic response in the theater. She then repeated her performance for the broadcast audience, launching a series of radio appearances that included her own show on BBC radio.
By 1944, Clark began appearing in British films, with Medal for the General (1944) and following with roles in more than 20 films through the 1940s and 50s, including Strawberry Roan (1944), I Know Where I'm Going (1945), and Here Come the Huggetts (1948). By the late 1940s Clark branched into recording and scored a number of hits in the U.K. during the 1950s, including "The Little Shoemaker" (1954), "Majorca" (1955), "Suddenly There's a Valley" (1955), and "With All My Heart" (1957). In 1958 she made her first concert appearance in Paris and soon began to record in French.
Desiring to escape the strictures of child stardom, she relocated to France and in 1961 married Claude Wolff, a promoter with Vogue Records. While she focused on her new career in France, she continued to achieve hit records in the U.K. into the early 1960s and thus developed a parallel career on both sides of the Channel. Her recording of "Sailor" became her first #1 hit in the U.K. in 1961, while such follow-up recordings as "Romeo" and "My Friend the Sea" landed her in the British top ten later that year. In addition to 1961's "Romeo", an international hit, such French recordings as "Ya Ya Twist" and "Chariot" (the original version of "I Will Follow Him") became smash hits in France in 1962.
After concentrating on her career in France in the early 1960s, Petula scored a major hit in the UK in 1964 with "Downtown", written by Tony Hatch. Released in the U.S. in late '64, "Downtown" went to #1 on the charts in early 1965 and became a million-seller. A string of trans-Atlantic hits followed including "I Know A Place", "My Love", "A Sign of the Times", "I Couldn't Live Without Your Love", "Color My World", "This is my Song", and "Don't Sleep in the Subway". In the U.S. the recording industry honored her with Grammy Awards for "Best Rock & Roll Record" for "Downtown" in 1964 and for "Best Contemporary Vocal Performance - Female" for "I Know a Place" in 1965. In 2003 her recording of "Downtown" was inducted into the Grammy Hall of Fame.
Petula revived her film career in the late 1960s, starring in two big musical films: Finian's Rainbow (1968) opposite Fred Astaire and Goodbye, Mr. Chips (1969) with Peter O'Toole. After this her output of hits diminished markedly, though she continued to record and make television appearances into the 1970s. By the mid 1970s she scaled back her career and devoted more time to her family, which included two daughters and a son.
In 1981 Petula launched a stage career, starring as Maria von Trapp in the revival of the musical "A Sound of Music" on London's West End. Later stage works included "Someone Like You" in 1989 and 1990, for which she wrote the music, "Blood Brothers", in which she made her Broadway debut in 1993, and in the West End and U.S. touring productions of Andrew Lloyd Webber's "Sunset Boulevard" (1995-2000). In 1998 Petula was honored by Queen Elizabeth II by being made a Commander of the Order of the British Empire (CBE).