In late 1964, Clark's success extended to the United States with a five-year run of career-defining, often upbeat singles, many written or co-written by Tony Hatch and Jackie Trent.

[8] As a child, Clark sang in the chapel choir and showed a talent for mimicry, impersonating Vera Lynn, Carmen Miranda and Sophie Tucker for her family and friends.

During the bombing the producer requested that someone perform to settle the jittery theatre audience and she volunteered a rendering of "Mighty Lak' a Rose" to an enthusiastic response.

[12][13] In addition to radio work, Clark frequently toured the United Kingdom with fellow child performer Julie Andrews.

She also became known as "Britain's Shirley Temple",[14] and was considered a mascot by the British Army, some of whose troops plastered her photos on their tanks for good luck as they advanced into battle.

[15] While she was performing at the Royal Albert Hall in London in 1944, Clark was discovered by the film director Maurice Elvey, who cast her, at the age of 12, as the precocious orphaned waif Irma in his war drama Medal for the General.

Additional film scores she composed include Entre ciel et mer (1963), Rêves d'enfant (1964), La bande à Bebel (1966),[29] and Pétain (1989).

Released in four separate languages in late 1964, "Downtown" was a success in the UK, France (in both the English and the French versions), the Netherlands, Germany, Australia, and Italy, and Rhodesia, Japan, and India as well.

While singing a duet of "On the Path of Glory", an antiwar song that she had composed, with guest Harry Belafonte, she took hold of his arm, to the dismay of a representative from the Chrysler Corporation (the show's sponsor), who feared that the moment would provoke racial backlash from Southern viewers.

[38][39] The Chrysler representative lost his job and the programme aired on 8 April 1968, four days after the assassination of Martin Luther King Jr., with high ratings, critical acclaim,[40] and a Primetime Emmy nomination.

It has erroneously been described as the first instance on American television of physical contact between a black man and a white woman,[41] forgetting many previous instances, including Frankie Lymon dancing with a white girl on Alan Freed's live ABC show The Big Beat on 19 July 1957,[42][43] Nancy Sinatra kissing Sammy Davis Jr., on her 1967 Movin' with Nancy TV special,[44] and Louis Armstrong shaking hands with "What's My Line?"

[45] To commemorate the 40th anniversary of the 1968 Belafonte telecast, Clark and Wolff appeared at the Paley Center for Media in Manhattan on 22 September 2008, to discuss the broadcast and its impact, following a showing of the programme.

In Finian's Rainbow (1968), she starred opposite Fred Astaire, and she was nominated for the Golden Globe Award for Best Actress – Motion Picture Musical or Comedy for her performance.

The following year, she was cast with Peter O'Toole in Goodbye, Mr. Chips (1969), a musical adaptation of the classic James Hilton novella.

[49] She has recalled that she and Karen Carpenter went to see Elvis Presley perform in Las Vegas and that afterwards "He was flirting with both of us, (saying) 'Wow, the two biggest girl pop stars in my dressing room.

On 6 February 1983, during a concert at the Albert Hall she gave a heart-rending performance of For All We Know in tribute to her friend Karen Carpenter who had died two days previously.

[citation needed] Clark recorded new material regularly throughout the 1970s, 1980s, and 1990s, and in 1992 released "Oxygen", a single produced by Andy Richards and written by Nik Kershaw.

In 2000, she presented a self-written, one-woman show, highlighting her life and career, to large critical and audience acclaim at the St. Denis Theatre in Montreal.

In 2004, she toured Australia and New Zealand, appeared at the Hilton in Atlantic City, New Jersey; the Hummingbird Centre in Toronto; Humphrey's in San Diego; and the Mohegan Sun Casino in Uncasville, Connecticut; and participated in a multiperformer tribute to the late Peggy Lee at the Hollywood Bowl.

Une Baladine (in English, a wandering minstrel), an authorised pictorial biography by Françoise Piazza, was published in France and Switzerland in October 2007, and the following month she promoted it in bookshops and at book fairs.

[citation needed] Open Your Heart: A Love Song Collection, a compilation of previously unreleased material and new and remixed recordings, was released in January 2009.

[citation needed] At the Montreux Jazz Festival on 14 July 2008 Clark joined with Paolo Nutini to perform "Goin' to Chicago Blues" in celebration of Quincy Jones' 75th birthday.

In 2010 she became president of the Hastings Musical Festival;[62] she toured Australia, New Zealand and Quebec to sell-out crowds,[citation needed] and appeared on the Vivement Dimanche show on French television, where she promised a return to Paris in the new year.

Her triple album Une Baladine included 10 new tracks and one new studio recording: "SOS Mozart", a writing collaboration of Gilbert Bécaud and Pierre Delanoë.

[citation needed] Both her album set and the new recording of "SOS Mozart" were produced by David Hadzis at the Arthanor Productions studio in Geneva and appeared on the French charts.

An internet poll was held, and the winner was Petula Lark, clearly a reference to the singer of the adopted anthem of New York City's urban area, "Downtown".

Two of the songs, "Crazy" and "Downtown", were performed in Jools Holland's New Year "Hootenanny" on 1 January 2013, along with her 1966 number-six hit, "I Couldn't Live Without Your Love".

[71][72] She made a cameo appearance in the 2017 London Heathrow Airport Christmas television commercial, accompanied by her song, "I Couldn't Live without Your Love".

[75] In March 2019 she was announced as returning to the West End stage in London for the first time in 20 years, performing in the upcoming revival of Mary Poppins as The Bird Woman.

In 1967 in Las Vegas, she was a witness at the wedding of her friend, French singer Charles Aznavour, alongside Sammy Davis Jr.