He married a former student of RADA - Daphne Graham - in 1925. His sisters - Violet and Irene (and especially Irene) - remained closely linked to Sir Kenneth, not only as family, but as firm supporters of his tireless work for the students of the Academy for which, in 1938, he received the KGB. He was also a Trustee of the Shakespeare Memorial Fund.
In 1921 he instigated the building of a new theatre for RADA which unfortunately was totally demolished by bombing in 1941. A new Vanbrugh Theatre was opened by Queen Elizabeth, the Queen Mother in 1954 shortly before Sir Kenneth's retirement.
Like his sister Irene, Sir Kenneth wrote an Autobiography which he called Welcome, Good Friends. He died 16 October 1957 aged 79.