Mary Orr, who died September 22 at 94, was a Broadway actress and playwright known for thrillers and comedies, but she will be remembered for a short story she wrote in 1947 for Cosmopolitan magazine, “The Wisdom of Eve.”

A tawdry tale about an aging actress whose understudy betrays her, the story became the basis for Joseph Mankiewicz’s script for the 1950 film “All About Eve.”

Orr, already a theater veteran, got her start on Broadway in 1939 as understudy to Claire Luce in “Of Mice and Men.” She claimed that the idea for “The Wisdom of Eve” came from the German actress Elizabeth Bergner, who said something similar once happened to her.

Although “All About Eve” garnered the Oscar for best film of 1950, Orr was reportedly paid just $3,000 for her story, and her name was left off the credits. With a good mystery writer’s instinct for intrigue, she suspected a conspiracy. “For the last few decades, it has been the delight of Broadway to lampoon Hollywood unmercifully,” she was quoted as saying by “Ohioana Authors,” a documentary project developed by the Ohio public radio station WOSU. “‘Eve’ was Hollywood’s chance to strike back.”

When the movie script was published in 1951, Orr was credited on its title page.

Orr’s first play was “Wallflower,” a comedy written with Reginald Denham, a veteran Broadway director who first met Orr while directing her in the 1940 production of “Jupiter Laughs.” “Wallflower” received its premiere on Broadway in 1944 and played for 192 performances.

Warner Brothers bought the script, and when the film appeared in 1948, the New York Times opined, “When a bad play is turned into a good film entertainment the people responsible for the transformation deserve to stand up and be counted.” (The director, for the record, was Frederick de Cordova, who much later directed “The Tonight Show Starring Johnny Carson.”)

Denham and Orr married in 1947 and wrote several more plays together that were produced on Broadway and on the London stage.

Orr was born in Brooklyn in 1911, but grew up in Canton, Ohio, where her father was president of Union Metal Manufacturing Co. (“Wallflower” was set in Ironville, a fictionalized version of Canton.) After spending a year at Syracuse University, she moved to New York to study at the American Academy of Dramatic Arts. After a few years appearing in smaller productions, she got to Broadway in 1939 as Luce’s understudy, and then began working with Denham.

The British-born Denham was a well-known director on both sides of the Atlantic, with a handful of British films and more than a score of Broadway productions to his credit. After “Wallflower,” though, his Broadway collaborations with Orr all closed after short runs. “Dark Hammock” managed just two performances in 1944; “Round Trip” had a short trip of seven performances in 1945; and “Be Your Age” managed only five performances in 1953.

These productions were more successful on tours out of town, and the two continued to collaborate in America and abroad.

While they lived on West 57th Street, their work rarely generated good reviews in New York. All too typical were Mel Gussow’s dismissive remarks in the Times about the “humdrum ménage” “Grass Widows,” which appeared off-off-Broadway in 1977: “long, tedious, and pathetic.”

Even in the provinces, reviewers could be savage. The Christian Science Monitor sniffed that “Wallflower” was “one of those machine-made farce-comedies put together by technically adept theater people.” And the Washington Post’s reviewer complained that the plot of “Dark Hammock” was “an especially transparent business … I doubt if any chair edges were appreciably worn by the cash customers in the National [Theater] last night.”

But they were pros and soldiered on. Their last collaboration was “Dead Giveaway: A Play of Suspense” in 1982; Denham died the following year, and Orr retired shortly after.

In 1967, Denham and Orr published “Footlights and Feathers,” a book about touring Australia and New Zealand with the play “Never Too Late,” directed by Denham and starring Orr.

Orr updated “The Wisdom of Eve” in a subsequent story in Cosmopolitan, “More About Eve,” and then turned the saga into her own play, “The Wisdom of Eve” (1964). Orr also wrote extensively for television and radio, and published four novels.

In 1970, “All About Eve” was produced on Broadway as the musical “Applause,” and Orr got a share of the credit for the plot.

She had no children, although she was close with her husband’s children and grandchildren, as well as with two nieces in Ohio.