Havelock-Allan was born at the family home of Blackwell Grange near Darlington, County Durham, and was educated at Charterhouse and schools in Switzerland. Before becoming a film producer, he worked as a stockbroker, jeweller, record company executive and cabaret manager.
In 1935, Havelock-Allan joined the short-lived British and Dominions Imperial Studios, producing films with them like Lancashire Luck (1937) until and even shortly after the studios burnt down in 1936. After working with her on This Man in Paris, Havelock-Allan married actress Valerie Hobson on 12 April 1939. Their sons were Simon Anthony Clerveaux Havelock-Allan (born May 1944) and Mark Havelock-Allan (born 4 April 1951). They divorced in 1952.
Havelock-Allan served as associated producer on the 1942 war film In Which We Serve, which starred Noël Coward, who co-directed the picture with David Lean. The film was shot by cinematographer Ronald Neame, who along with Havelock-Allan and Lean, founded their own company, Cineguild. Cineguild's first production was a film adaptation of Coward's 1939 play This Happy Breed, which was produced by Coward, directed by Lean, and shot by Neame. All three partners -- Havelock-Allan, Lean and Neame -- collaborated on the script.
The exact same combination of talents created the 1945 film adaptation of Coward's comedy Blithe Spirit. The quartet then produced the classic Brief Encounter, with Havelock-Allan and Neame sharing producing duties with Coward, with Coward helping write the script, an adaption of his 1936 one-act play Still Life. The film won the Palme d'Or at the 1946 Cannes Film Festival while lead Celia Johnson was nominated for an Academy Award for Best Actress in the 1947 awards. In 1999, Brief Encounter came in second in a British Film Institute poll of the top 100 British films.
Havelock-Allan, Lean and Neame moved away from Coward and next filmed two classic by Charles Dickens, creating two classics of British cinema in the process. Both Great Expectations (1946) and Oliver Twist (1948) brought the three Oscar nominations for the Academy Award for Best Adapted Screenplay.
He left Cineguild and founded Constellation Films in 1947. He later co-founded British Home Entertainment with Lord Brabourne in 1960. He later was reunited with David Lean when he produced the great director's penultimate film, Ryan's Daughter (1970).
Havelock-Allan married second wife María Teresa Consuelo Sara Ruiz de Villafranca (Sara Ruiz de Villafranca), a daughter of the former Spanish Ambassador to Chile and Brazil, on 26 June 1979.
In 1975, he had succeeded to his childless brother's baronetcy and on his own death in 2003, aged 98, his title passed to his son, Mark.
All as producer, unless otherwise stated: