Starting as a journalist, her first published work of fiction is thought to be “The Customs Lounge”, a science fiction story published in the September 1963 issue of If, under the byline “E.A. Proulx”. Another contender, a year later, was a science fiction story called “All the Pretty Little Horses”, which appeared in teen magazine Seventeen in June 1964. She subsequently published stories in Esquire magazine and Gray’s Sporting Journal in the late 1970s, eventually publishing her first collection in 1988 and her first novel in 1992. Subsequently, she was awarded NEA (in 1992) and Guggenheim (in 1993) fellowships.

Proulx lived for more than 30 years in Vermont, has married and divorced three times, and has three sons and a daughter (Jonathan, Gillis, Morgan, and Sylvia). In 1994 she moved to Saratoga, Wyoming, spending part of the year in northern Newfoundland on a small cove adjacent to L’Anse aux Meadows. Proulx now lives in Port Townsend, Washington.

In 1997, Annie Proulx was awarded the Dos Passos Prize, a mid-career award for American writers. Proulx has twice won the O. Henry Prize for the year’s best short story. In 1998, she won for “Brokeback Mountain”, which had appeared in The New Yorker on October 13, 1997. Proulx won again the following year for “The Mud Below,” which appeared in The New Yorker June 22 and 29, 1999. Both appear in her 1999 collection of short stories, Close Range: Wyoming Stories. The lead story in this collection, entitled “The Half-Skinned Steer”, was selected by author Garrison Keillor for inclusion in The Best American Short Stories 1998, (Proulx herself edited the 1997 edition of this series) and later by novelist John Updike for inclusion in The Best American Short Stories of the Century (1999). In 2001 Proulx was one of the writers heavily criticized by Brian Reynolds Myers in his polemical work A Reader’s Manifesto.

In 2007, the composer Charles Wuorinen approached Proulx with the idea of turning her short story “Brokeback Mountain” into an opera. The opera of the same name with a libretto by Proulx herself premiered January 28, 2014 at the Teatro Real in Madrid. It was praised for an often brilliant adaptation that clearly conveyed the text of the libretto with music that is rich in imagination and variety. In 2017 she received the Fitzgerald Award for that year for Achievement in American Literature.