Margaret Booth (January 16, 1898 – October 28, 2002) was an American film editor. In a career lasting seven decades, Booth was most associated with Metro-Goldwyn-Mayer (MGM).

Born in Los Angeles, Margaret was the younger sister of actor Elmer Booth, who starred in several films for D. W. Griffith. Elmer was killed in a car accident, and Griffith later employed Margaret as a negative cutter. Booth worked with Griffith's studio for several years. She later joined Louis B. Mayer's namesake studio, where she was mentored by film director John M. Stahl. In 1924, Mayer merged his studio with Metro Pictures and Goldwyn Pictures to form Metro-Goldwyn-Mayer (MGM). Stahl and Booth joined MGM, where she edited several of his films. Stahl later left MGM, while Booth stayed. She was named the studio's first official film editor by Irving Thalberg, MGM's then-production head. In 1935, Booth received an Academy Award nomination for Best Film Editing on Mutiny on the Bounty.

After Thalberg's death, Mayer appointed Booth as the studio's supervising film editor, a position she held for nearly three decades. In 1968, Booth retired from MGM, and was hired by Ray Stark as a supervising film editor for his studio Rastar Productions. In 1977, Booth was awarded an Academy Honorary Award for her decades-long contributions as a film editor. She received her last credit as an executive producer for The Slugger's Wife (1985). Booth became a centenarian in 1998, and died in 2002 at the age of 104.

Margaret Booth was born on January 16, 1898, in Los Angeles to Edward J. Booth, Sr. and Margaret A. Boland. Her older brother was Elmer Booth, who was an actor for D. W. Griffith and the breadwinner for the family. On June 16, 1915, Elmer was riding with actor George Siegmann in a car driven by Tod Browning. Due to the heavy fog that day, Browning did not see the rear lamp of an oncoming train. Browning's car was hit by a train of the Salt Lake Railroad, killing Elmer instantly. Browning and Siegmann however survived but suffered serious injuries. At Elmer's funeral, Griffith delivered an eulogy and approached Margaret with a job offer as a film joiner (also known as a negative cutter) to provide income for the family. Margaret never forgave Browning for her brother's death.

By 1915, Booth had graduated from Los Angeles High School. Griffith hired Booth on a salary for ten dollars a week as one of several female editors for his studio. Booth remembered years later, "...in the old days we had to cut negative by eye. We matched the print to the negative without any edge numbers. We had to match the action. Sometimes there'd be a tiny pinpoint on the negative, and then you knew you were right, but it was very tedious work." One of the films she worked on was Orphans of the Storm (1921) starring Lillian Gish. After a few months, Booth worked for Paramount Pictures' editing department, assembling the tinted sections for release prints.

In 1921, Booth began working for Louis B. Mayer at his namesake film production studio. Mayer had hired John M. Stahl when Edward Small, who was Stahl's publicity agent, inquired why there were no hired Jewish directors. Inside the editing room, Booth observed Stahl, and because he was a perfectionist, Stahl would shoot multiple takes of several scenes and leave outtake footage literally on the cutting room floor. At the end of the day, Booth assembled the outtakes and stayed overnight to practice her cutting techniques. One day, Stahl was frustrated when he couldn't make a scene work. After he left, Booth took her own approach; when Stahl screened her work, he was impressed and hired her immediately as his editorial assistant. For Stahl, she edited The Gay Deceiver (1926), Lovers? (1927), and In Old Kentucky (1927).

Stahl personally mentored Booth on the craft of film editing, explaining the exact purpose for his editing decisions. Booth reflected, "He taught the value of a scene. When a scene drops or doesn't drop, and when it sustains. You have to feel this, intrusively, in your work." In 1924, Mayer merged with Metro Pictures and Goldwyn Pictures to form a new conglomerate film production studio known as Metro-Goldwyn-Mayer (MGM). Stahl stayed with MGM for several years, but when he left the studio in 1927, he asked Booth to join him but she declined. Booth stated, "I went on to working at M-G-M, mostly with [Irving] Thalberg—the greatest man who was ever in pictures. M-G-M was like home to me." Her editing skills were appreciated by Thalberg, MGM's head of production, that he asked her if she would consider directing. However, she was not interested. Regardless, according to film historian Cari Beauchamp, Thalberg was the first known person to call cutters "film editors," starting with Booth. Her first official editing credit was for the 1929 part-talkie film The Bridge of San Luis Rey.

At MGM, Booth edited several films starring Greta Garbo, including Camille (1936). She also edited Wise Girls (1929), The Barretts of Wimpole Street (1934), and Romeo and Juliet (1936). Booth received her only competitive Academy Award nomination for Best Film Editing on Mutiny on the Bounty (1935).