[2] Whiting was born on 30 June 1950,[3] in Wood Green, moving with his two sisters to Holloway, another area of North London, England.

Leonard went on to attend St. Richard of Chichester School, Camden Town, leaving in 1967, before his 17th birthday, to begin work on Romeo and Juliet (1968).

[4][5][6][7][8] Whiting had some success as a child singer, almost winning Butlin's Talent Contest (he came second) hosted in the holiday camp's packed out Gaiety Theatre.

[10][11][12] Director Franco Zeffirelli described his discovery, from 300 youngsters who had auditioned over a period of more than three months as: "He has a magnificent face, gentle melancholy, sweet, the kind of idealistic young man Romeo ought to be.

In 1973, he played the title role in the made-for-TV film Frankenstein: The True Story alongside an all-star cast that included James Mason, Ralph Richardson, John Gielgud, Jane Seymour, Agnes Moorehead and David McCallum.

In 2014, he reunited professionally with his friend Olivia Hussey for Social Suicide (2015), their first film together in the 46 years since the Franco Zeffirelli production of Romeo and Juliet.

[19] Following his divorce from Dahmen in 1977, Whiting had a relationship with theatre designer Valerie Marion Tobin, who gave birth to their daughter Charlotte.