O'Hara is regarded as a leading figure in the New York School, an informal group of artists, writers, and musicians who drew inspiration from jazz, surrealism, abstract expressionism, action painting, and contemporary avant-garde art movements.

[1] Poet and critic Mark Doty has said O'Hara's poetry is "urbane, ironic, sometimes genuinely celebratory and often wildly funny" containing "material and associations alien to academic verse" such as "the camp icons of movie stars of the twenties and thirties, the daily landscape of social activity in Manhattan, jazz music, telephone calls from friends".

He grew up believing his birthday was in June, when, in fact, he had been born in March—as his parents disguised his true date of birth because he had been conceived out of wedlock.

[4] He studied piano at the New England Conservatory in Boston from 1941 to 1944 and served in the U.S. Navy in the South Pacific and Japan as a sonarman on the destroyer USS Nicholas during World War II.

[6] His favorite poets were Pierre Reverdy,[7] Arthur Rimbaud, Stéphane Mallarmé, Boris Pasternak, and Vladimir Mayakovsky.

He was a friend of the artists Norman Bluhm, Mike Goldberg, Grace Hartigan, Alex Katz, Willem de Kooning, Joan Mitchell, and Larry Rivers.

Immersion in regimented daily routine, first at Catholic school, then in the Navy, enabled him to separate himself from situations and make witty, often singularly perceptive commentary.

This skill at scrutinizing and recording amid the bustle and churn of daily life would later be one of the important aspects that shaped O'Hara as an urban poet, writing off the cuff.

John Ashbery says he witnessed O'Hara "Dashing poems off at odd moments—in his office at the Museum of Modern Art, in the street at lunchtime, or even in a room full of people—he would then put them away in drawers and cartons and half forget them.

"[10] In the summer of 1951, O'Hara read a manifesto in The Kenyon Review written by the poet, novelist and anarchistic social critic Paul Goodman.

In the essay, Goodman argues that the postwar American "advanced guard" writers must articulate the deep-seated, personal disquiet felt across the culture but left unvoiced.

He says, in response to academic overemphasis on form, "As for measure and other technical apparatus, that's just common sense: if you're going to buy a pair of pants you want them to be tight enough so everyone will want to go to bed with you.

Ashbery says, "The poetry that meant the most to him when he began writing was either French – Rimbaud, Mallarmé, the Surrealists: poets who speak the language of every day into the reader's dream – or Russian – Pasternak and especially Mayakovsky, for whom he picked up what James Schuyler has called the 'intimate yell.

[15][16] Ashbery says, "Frank O'Hara's concept of the poem as the chronicle of the creative act that produces it was strengthened by his intimate experience of Pollock's, Kline's, and de Kooning's great paintings of the late '40s and early '50s and of the imaginative realism of painters like Jane Freilicher and Larry Rivers.

"[14] According to Marjorie Perloff in her book Frank O'Hara, Poet among Painters, he and Williams both use everyday language and simple statements split at irregular intervals.

[27] The painter Larry Rivers, a longtime friend and lover,[28] delivered one of the eulogies, along with Bill Berkson, Edwin Denby, and René d'Harnoncourt.

[34] In the last episode of the series Normal People, based on Sally Rooney's novel of the same name, Connell's gift for Marianne's birthday is said to be a Frank O'Hara's collection of poetry.

[citation needed] On June 10, 2014, a plaque was unveiled outside one of O'Hara's New York City residences, at 441 East Ninth Street.