Born to a middle-class Hampstead family, Beaton always had arisocratic tastes and ambitions. Beautiful as a child, he identified with the world of the stage from an early age, and as was usual, performed female roles in school plays and theatricals, but rather too well. He entered Harrow in 1918, where he dressed flamboyantly and wore make-up.

Portrait and fashion photographer, stage and costume designer, illustrator, diarist, and conversionalist. He produced notable portraits studies and designed sets and costumes for plays and films, for example the London and New York production of My Fair Lady; and scenery and costumes for balletts. He he got an Oscar prize for the costumes for the film versions of My Fair Lady.

In the 1950s and 1960s his career was boosted by the regular patronage of the British royal family, to whom he had provided flattering images since 1939. During the 1950s and 1960s he was a regular photographer to the British royal family, and he was knighted in 1971. He occupied the position of someone wishing to be "in" society but always nervous of reactions to his homosexuality.

He had a long and passionate obsession with Greta Garbo, but, in his own words, "I'm really much more fond of men." His many male lovers included the wealthy patron of the arts, Peter Watson. Beaton also claimed, credibly, that he slept with actor Gary Cooper.