Hawkins joined the Royal Welch Fusiliers in 1940, was commissioned and served with the Second British Division in India. In 1944 he was seconded to GHQ India and soon afterwards succeeded to the command, as a colonel, of ENSA administration in India and South East Asia. He was demobilized in 1946.
He died three months after an operation to insert an artificial voice box in April 1973.
He was a student at the Italia Conti Drama School in London, England.
He was awarded the CBE (Commander of the Order of the British Empire) in the 1958 Queen's Honours List for his services to drama.
He was voted Number 1 star at the British Box Office in 1954.
His memorial service took place on what would have been his sixty-third birthday on 14 September 1973 at St. Martin-in-the-Fields, London. The address was read by Kenneth More and Richard Attenborough read the lesson.
In his will published on September 20 1973 he left just £13,019 gross but the net amount was shown as nil. This was a result of high UK taxes and a reduction in his income following the surgery in 1966 which resulted in the loss of his voice. The family home at 34 Ennismore Gardens, South Kensington was left to his wife and his three children were provided for through a trust fund.
Initially sought for the role of Melville Farr in Victim (1961), Hawkins turned the role down because he thought the part might compromise his masculine screen image. Dirk Bogarde, who eventually played Farr, opined that Hawkins feared the role of a gay barrister would "prejudice his chances of a knighthood.".
Made Guns at Batasi (1964), Judith (1966), Masquerade (1965) and Poppies Are Also Flowers (1966) (TV) while suffering from cancer of the larynx. By the time he started filming "The Wednesday Play: The Trial and Torture of Sir John Rampayne (#1.37)" (1965), Hawkins had begun to cough up blood. His final role using his own voice was in a few episodes of "Dr. Kildare" (1961), where he managed to give a very accurate performance as a man who had just suffered a heart attack.
Provided the official celebrity opening of the Aldersley Municipal Sports Stadium, Wolverhampton on 9 June 1956. The stadium now forms part of Aldersley Leisure Village.
Resented the idea that he was typecast in war movies, pointing out in his 1973 autobiography "Anything for a Quiet Life" that he had in fact played fewer military roles than John Mills, Trevor Howard and Richard Attenborough.
Underwent cobalt treatment for a secondary condition of the larynx in 1959 after making The League of Gentlemen (1960). Afterwards he took voice coaching and reduced the number of cigarettes he smoked each day from about sixty to five. However, while filming Guns at Batasi (1964) five years later his voice began to fail. It was not until Christmas 1965 that he was diagnosed with throat cancer, by which time the only possible treatment was a total laryngectomy.