He is a prominent art collector who has, as a result of his three divorces, bought many of his favourite paintings four times. He at one time had the largest private collection of the paintings of Charles Conder in the world and he is a great lover of the Flemish symbolist painter Jan Frans De Boever, relishing his role as 'President for Life' of the De Boever Society. He himself is a landscape painter and his pictures are in private and public collections both in his homeland and abroad. Humphries has also been the subject of numerous portraits by artist friends, including Clifton Pugh (1958, National Portrait Gallery) and John Brack (in the character of Edna Everage, 1969, Art Gallery of New South Wales).