Born in Belfast in April 1916, Dillon moved to London in 1934 and while working in various jobs, he used his earnings to buy art materials and visit galleries. He first visited Connemara in 1939, where the landscape and the people were to provide inspiration for his painting, and was to spend much time in the Roundstone area with George Campbell. He had many exhibitions in London, Dublin and Belfast, and also exhibited in America. A large Retrospective Exhibition of his work consisting of 104 works was organised by the two Arts Councils, Belfast and Dublin, in 1972 following his death in 1971.