Cleo Laine was born Clementine Dinah Bullock on October 28, 1927, in Islington, London, England. Her parents, Alexander Sylvan Campbell and Minnie Bullock (née Hitching),were from Jamaica and England, respectively. Her father was a building laborer and busker, while her mother ran boarding houses.
Cleo's early life was marked by her love for cinema and musicals, and she was inspired by actresses Deanna Durbin and Judy Garland. She began performing at the age of 12, playing a street urchin in the 1940 film "The Thief of Bagdad," alongside her older sister, Sylvia Laine, and younger brother, Alexander Laine.
As a teenager, Cleo worked as an apprentice hairdresser, a library clerk, and in a pawnbroker's establishment. She married roof tiler George Langridge at the age of 24, but the union ended in divorce 11 years later, in 1957.
Cleo's love for jazz led her to audition for the Johnny Dankworth Seven jazz ensemble at the age of 24. She became the lead singer of Dankworth's big bands and performed with him for many years, during which time she developed her unique vocal style and range.
In the 1950s, Cleo began to make a name for herself in the music industry, performing with jazz legends such as Ella Fitzgerald, Sarah Vaughan, and Lena Horne. She also took singing lessons from Dankworth, who helped her to develop her technique and expand her vocal range.
Cleo's marriage to Johnny Dankworth in 1958 lasted for over 50 years, until his death in 2010. During their marriage, they collaborated on many projects, including several albums and live performances.
In the 1960s and 1970s, Cleo expanded her repertoire to include classical music, performing works by composers such as Weill and Schoenberg. She also collaborated with other jazz legends, including Dudley Moore, Count Basie, Ted Heath, Mel Tormé, Dizzy Gillespie, and Ray Charles.
Throughout her career, Cleo has released over 75 albums and has performed in numerous concerts and TV shows. She has won several awards, including a Grammy Award for Best Female Jazz Vocal Performance in 1986.