Born the son of a graphic designer and chromolithographer, Gaunt dabbled in drawing and writing as a youth.
In 1914, after winning a literary contest in The Connoisseur for an essay on Shakespeare's The Tempest, his thoughts seriously turned to becoming a critic.
The following year he attended Worcester College, Oxford, where he read modern history and participated in the Art Society.
Graduating with honours in 1922, he studied at the Ruskin School of Drawing and wrote reviews of art exhibitions.
During the Second World-War, he took a special appointment for the war effort and researched for the book The Aesthetic Adventure.