Philip James Ayres (28 July 1944 – 15 August 2021) was an Australian biographer and literary historian, described by High Court Justice Dyson Heydon AC as "one of the best biographers this country has ever produced". Of German and Anglo-Scottish cultural heritage, he was a Fellow of the Royal Historical Society (London), a Fellow of the Australian Academy of the Humanities, and a recipient of the Centenary Medal in 2001 for contributions to literature.