

Soon after arriving in New York, he was employed at the front desk of the Museum of Modern Art and began to write seriously. Known throughout his life for his extreme sociability, passion, and warmth, O'Hara had hundreds of friends and lovers throughout his life, many from the New York art and poetry worlds. It was in New York that he began teaching at The New School. That autumn O'Hara moved into an apartment in New York City with Joe LeSueur, who would be his roommate and sometime lover for the next 11 years. While at Michigan, he won a Hopwood Award and received his M.A. He then attended graduate school at the University of Michigan in Ann Arbor. Despite his love of music, O'Hara changed his major and graduated from Harvard in 1950 with a degree in English. While at Harvard, O'Hara met John Ashbery and began publishing poems in the Harvard Advocate. His favorite poets were Arthur Rimbaud, Stéphane Mallarmé, Boris Pasternak, and Vladimir Mayakovsky.

O'Hara was heavily influenced by visual art and by contemporary music, which was his first love (he remained a fine piano player all his life and would often shock new partners by suddenly playing swathes of Rachmaninoff when visiting them). He regularly attended classes in philosophy and theology, while writing impulsively in his spare time. Although O'Hara majored in music and did some composing, his attendance was irregular and his interests disparate.

With the funding made available to veterans he attended Harvard University, where artist and writer Edward Gorey was his roommate. He studied piano at the New England Conservatory in Boston from 1941 to 1944 and served in the South Pacific and Japan as a sonarman on the destroyer USS Nicholas during World War II. He grew up believing he had been born in June, but in fact had been born in March, his parents having disguised his true date of birth because he was conceived out of wedlock. Frank O'Hara, the son of Russell Joseph O'Hara and Katherine (née Broderick) was born on March 27, 1926, at Maryland General Hospital, Baltimore and grew up in Grafton, Massachusetts.
