Campbell, Sir Cecil James Henry (1891–1952), company director, sportsman, and soldier, was born 4 May 1891, the second son of James Henry Mussen Campbell (qv), 1st Baron Glenavy, and his wife Emily (née McCullough). Following education at Shrewsbury School and St John's College, Oxford, he was called to the English bar at Gray's Inn in 1917. A talented tennis player, he represented successively Oxford University, the British Isles, the Irish Free State, and Egypt. He reached the quarter-finals of the men's singles championship at Wimbledon (1921–3) and was the only player to take a set off W. M. Johnston in 1923. In 1919 he won the Irish men's singles title and in 1921 won the singles, doubles (with J. F. Stokes), and mixed doubles (with Miss E. Ryan). He had similar success in Egypt and was a noted contender for the Doherty cup hosted at the Gezira Sporting Club. He represented the Irish Free State in the Davis cup: against India and France in 1923, South Africa in 1927 and the Netherlands in 1928. Jean Borotra described him as a ‘great player with a lion's heart and a glorious forehand drive’.
Campbell went about 1920 to Egypt, where he served in the Royal Army Supply Corps. He was legal secretary to the Egyptian government's financial adviser (1922–30) and legal counsellor to the British residency (1930–32) before becoming managing director of the Marconi Radio Telegraph (Egypt) Company (1933–47) and the Eastern Telegraph (Egypt) Company. Attached to the Intelligence Corps of the British Army during the Second World War, he subsequently became president of the chamber of commerce of Egypt (1945–52) and held many key directorships, including the chairmanship of both the local board of Anglo-Egyptian Oil and the Near East board of the Gresham Life Assurance Society Ltd. Highly influential in Egyptian business and political circles, he was often a peacemaker in Anglo–Egyptian disputes. He was created CMG in 1930 and KBE in 1947. In April 1950 he was publicly outspoken in his criticism of the Egyptian tax authorities. Campbell recognised the need for development in Egyptian industry but believed that such development was hampered by poor legislation. He felt that the situation was compounded by the rushed policy of ‘Egyptianisation’, which had led to a lack of qualified staff in government and industry. In May 1950 he was elected to the board of the National Bank of Egypt. His obituary noted that he was a humorous and engaging conversationalist and in great demand as an after-dinner speaker.
In 1925 Campbell married Lavender Letts, daughter of Sydney Letts of Little Bardfield Hall, Essex (divorced 1934). His second marriage was to Mrs Martha Evelyn Audrey Courtenay in 1934 (divorced 1942). Campbell shot himself 11 May 1952 at his home in Zamalek, Cairo. It was reported that he had been in poor health for some time.