She played piano at a dancing school to earn money, while she wrote poetry.
She sold her first poem to Vanity Fair in 1914, on the strength of which she became an editorial assistant for Vogue. Two years later, she became a theater critic back at Vanity Fair.
Her clever reviews (often in the form of poems) made her popular. But she tended to be hard on the productions she reviewed (bad for Broadway advertising in Vanity Fair) and in 1920 was terminated.
Parker continued to write for The New Yorker and in the 1920s alone published more than 300 poems there and elsewhere. She said her inspiration was the wry lyric poetry of Millay (quoted in part in Parker's NY Times obituary, which includes many other wise and witty sayings):
Like everybody else was then, I was following in the footsteps of Edna St Vincent Millay, unhappily in my own horrible sneakers.... We were all being dashing and gallant, declaring that we weren't virgins, whether we were or not. Beautiful as she was, Miss Millay did a great deal of harm with her double-burning candles. She made poetry seem so easy that we could all do it. But, of course, we couldn't.She was perhaps the best-known member of the Algonquin Roundtable, which met to share witty putdowns of their contemporaries. Parker said later that the two (other) members of the Roundtable who were most aware of the world around them were the humorist Robert Benchley and the journalist Heywood Broun, founder of the Newspaper Guild.
Her books of poems include Enough Rope (1926) and Death and Taxes (1931). She also wrote screenplays with her husband, Alan Campbell, whom she divorced in 1947 and remarried in 1950. When she died in 1967 at 73, she bequeathed her estate to Dr. Martin Luther King Jr., who was assassinated the year after she died.
She suggested as the epitaph for her tombstone:
WHEREVER SHE WENT, including here, it was against her better judgment.