He studied at the University of Melbourne from 1946, graduating BA with honours. He married in 1947, and worked as a freelance writer, then in advertising, then as Public Relations Manager with ICI in Melbourne.[5]
He was Director of Melbourne University Press from 1962 to 1989. He wrote about these years in his memoir Final Proof (2010).
In the September 1993 edition of Quadrant he wrote an attack on the six-volume History of Australia by Manning Clark, which Melbourne University Press had published between 1962 and 1987.[6] Among other things he said Clark's history was "over a million printed English words, probably unrivalled in their power to combine the non sequitur with the anticlimax, and to wring the last drops from a series of foregone conclusions".[7] The article aroused considerable controversy, which Ryan dealt with in a subsequent article in Quadrant in October 1994.[8]
He wrote a monthly column for Quadrant from March 1994 to October 2015. A selection of these columns was published in 2011 under the title It Strikes Me. He died on 13 December 2015 at the age of 92.[9]