She was born Justine Kay Kendall McCarthy, at Stanley House, Hull Road, in Withernsea, a coastal resort in the East Riding of Yorkshire, England. Kendall’s father was Terrence “Terry” McCarthy (aka Terry Kendall), the vaudevillian son of music hall star Marie Kendall. Kay’s mother was the former Gladys Drewery. She had two elder siblings, Terrence Justin “Terry” Kendall McCarthy (born 1923) and Patricia Kim “Pat” Kendall McCarthy (aka Kim Kendall, born 1925). By her father’s second marriage to his professional dancing partner, Dora Spencer, she had a younger half-brother, Cavan Spencer Kendall McCarthy (aka Cavan Kendall) (1942-1999). Young Justine attended various schools, including St Leonard’s (Brighton), St Margaret’s (near Oban, Scotland), and the Lydia Kyasht Dancing Academy (London). The actress’s distinctive nose, an aristocratic swoop, was the result of plastic surgery after a car crash. As she told Dirk Bogarde, the surgeon had only two noses in his repertoire, “this one and the other one.” The one she chose, Kendall explained, made it difficult to photograph her in profile. Her first major screen role was in the Sid Field, Petula Clark London Town, notable for being one of the costliest flops in British film history. She co-starred with Clark again in the drama film Dance Hall (1950), and was featured in a quick succession of minor films before gaining fame in Genevieve (1953). She followed this up with the even more popular first film in the Doctor series, the comedy Doctor in the House (1954) with Dirk Bogarde. She was under contract to the Rank Organisation but unhappy with the parts offered, turning down Value For Money (1955), As Long As You’re Happy (1955) and Doctor at Sea (1955).

She did appear in the drama Simon and Laura (1955) with Peter Finch; the comedy Abdulla the Great (1955) with Sydney Chaplin and Gregory Ratoff; and the epic historical film The Adventures of Quentin Durward (1955), with Robert Taylor and Robert Morley. In October and November 1957, she appeared in two episodes of the short-lived American television series The Polly Bergen Show. In 1958, Kendall won a Golden Globe Award for her performance as Lady Sybil Wren in Les Girls – probably one of the best-known films of her career – the story of three showgirls in postwar Paris (with Mitzi Gaynor and Taina Elg). The following year, she starred opposite Harrison in the comedy The Reluctant Debutante. Kendall died in 1959, aged 32, soon after completing her last film, the comedy Once More, with Feeling! (1960), starring opposite Yul Brynner. Early in her career, Kendall had a lengthy romance with actor Sydney Chaplin, the second son of actor Charlie Chaplin by his second wife, actress Lita Grey. She also had affairs with a Swedish prince and grocery heir James Sainsbury and reportedly had a romance with the future Prince Philip, Duke of Edinburgh. In 1955, she starred opposite Harrison in The Constant Husband, and an affair soon followed. Harrison was married to actress Lilli Palmer at the time. However, when he learned from Kendall’s doctor that she had been diagnosed with myeloid leukaemia, he and Palmer agreed to divorce so he could marry Kendall and provide for her care. Kendall was never told of her illness and ended up believing she merely had an iron deficiency. As for the divorce, Palmer said she was not upset because she had a lover, too. Palmer and Harrison planned to remarry after Kendall’s death, but Palmer ended up falling in love with her companion, actor Carlos Thompson, and married him instead. Kendall was buried in the churchyard of St John-at-Hampstead Church, Hampstead, London. On Sunday 22 September 2013 her final resting place was restored by The Music Hall Guild of Great Britain and America.