Over the years Cahill was given several awards. He received an honorary Doctor of Laws (LL.D.) from the University of Sydney in 1952, an honorary Doctor of Science (D.Sc.) from the New South Wales University of Technology in 1955, and an honorary Doctor of Literature (D.Litt.) from the University of New England in 1956. On 17 December 1958, the City of Sydney decided to name the new highway across Circular Quay as the "Cahill Expressway", and Cahill was present when the Blue Mountains City Council officially named the "Cahills Lookout" in Katoomba on 6 June 1959. In 1961 the Municipality of Rockdale in his former electorate decided to name the new park in Wolli Creek as "Cahill Park".