When champion sharpshooter Frank Butler (Howard Keel), his personal manager Charlie Davenport (Keenan Wynn) and Buffalo Bill Cody's Wild West troupe of headliners arrive in Cincinnati to put on a show, the town breaks out in celebration. The arrival of the troupe brings joy to everyone except Foster Wilson (Clinton Sundberg), a persnickety hotel owner who will be housing the troupe.

Wilson later joins in the celebration, however, when Annie Oakley (Betty Hutton), a bedraggled sharp shooting tomboy, and her ragtag gang of siblings check into the hotel. Impressed by Annie's shooting abilities, Wilson quickly arranges a match between her and Frank, whom he calls a "swollen-headed stiff." Annie falls instantly in love with Frank, and the show gets underway when Buffalo Bill (Louis Calhern) introduces the two sharpshooters.

The crowd heckles Annie, believing that she is no match for Frank, but to everyone's astonishment, she outdraws her opponent and wins the contest. Angered by the defeat, Frank refuses to accept Buffalo Bill's suggestion that Annie join the touring show as his assistant. Annie eventually persuades Frank to let her join, and the two sharpshooters become a successful team. After shedding her country clothes and making herself more attractive, Annie tries to impress Frank by learning how to read.

While a romance blossoms between Frank and Annie, Buffalo Bill grows increasingly concerned that his show is losing money and appeal. Realizing that his troubles stem from his competitor, Pawnee Bill (Edward Arnold), Buffalo Bill decides to spice up the show by giving Annie top billing. Annie does well in a solo performance, but her success prompts Frank to doubt his star status and long for the days when Annie was a "sweet, simple little girl."

After the show, Annie is introduced to Sitting Bull (J. Carrol Naish), an Indian chief who decides to adopt Annie as his daughter and finance the show. Following her induction into Chief Sitting Bull's tribe, Annie receives a farewell letter from Frank, who believes that Annie has lost interest in him. A short time later, Buffalo Bill takes his cowboy and Indian show to Europe, where Annie and Chief Sitting Bull become an instant sensation. Frank, meanwhile, joins Pawnee Bill's troupe.

Despite the show's critical success in Europe, Buffalo Bill continues to lose money. When Buffalo Bill realizes that his star is lovesick, he decides to pack up the show and return home. In New York, Annie learns that Frank is now consorting with debutantes, and she is certain that he will reject her. Buffalo Bill tries to rescue his show by negotiating a merger with Pawnee Bill and by selling Annie's valuable medals. Annie and Frank eventually reconcile, but when Frank sees all her awards, he becomes jealous of her success and they argue over who is the better shooter. Annie and Frank decide to settle their argument in a shooting match, but before the match, Chief Sitting Bull, hoping to forge a permanent reconciliation between the two sweethearts, persuades Annie to deliberately lose. The strategy works, and Frank, with his pride restored, finally proposes marriage to Annie.

Judy Garland was originally cast as Annie but took ill during early filming. A May 13, 1949 Hollywood Reporter news item stated that Betty Garrett was a "hot contender" for Judy's replacement. Modern sources note that Judy Canova, Doris Day and Betty Grable were considered as possible replacements, and that June Allyson and Ginger Rogers expressed interest in playing the role. According to records of the M-G-M legal department, as reproduced in a modern source, a $100,000 contract was drawn up on June 21, 1949 for the loan-out of Betty from Paramount.

Frank Morgan was originally cast as Buffalo Bill but died shortly after filming began. He was replaced by Louis Calhern.

Director Busby Berkeley was also replaced, by George Sidney. Charles Walters had been set to direct after Berkeley left, but was fired before he could actually shoot any of it.

M-G-M postponed production on "Annie Get Your Gun" until Betty finished filming "Let's Dance" at Paramount. However, Betty reported to M-G-M for costume fittings and other meetings after hours at night and Sundays, in between filming for "Let's Dance".

Betty received shooting lessons from trick shot artist Dorothy Lind in preparation for her role as Annie Oakley.

Betty recorded the ten numbers and two reprises which make up her vocal performance in only six days. During those six days, between recordings, were sandwiched rehearsals with dance director Robert Alton.

Betty sprained her back and fractured two vertebrae during rehearsals for the "I'm An Indian, Too" dance routine.

Howard Keel broke his leg during filming when a horse fell on it.

Betty reportedly did not get along with co-star Howard Keel. In an August 11, 1972 interview with the Courier Times, Keel was quoted as saying, "Betty's talented, but nobody could hold her down. She had to devour everything. If she didn't wipe herself out completely, she didn't think she'd done a good enough job. Sometimes she was sweet...othertimes, murder!"

"Annie Get Your Gun" grossed $8,000,000 at the box office, with an additional $8,000,000 in rental sales worldwide.

Despite its popularity, this film was unavailable in any form from 1973 until 2000 due to legal tangling between the Irving Berlin Estate and M-G-M. It was finally re-released in 2000.

The original Broadway show "Annie Get Your Gun" opened at the Imperial Theater on May 16, 1946 starring Ethel Merman and Ray Middleton and ran for 1,147 performances.

Rights to the Broadway show cost $650,000, a record at the time.