Born in New York City, Busch began his writing career in the early twenties, when he went to work for Time Magazine (co-founded by Busch's cousin, Briton Hadden). Before departing for Hollywood a decade later, Busch had risen to editor at the weekly, working simultaneously for The New Yorker, where he contributed profiles on famous Americans. (These articles were collected into his first book, the non-fiction Twenty-One Americans.)

In 1932, realizing he had gone as far as he was likely to go as a New York-based magazine writer/editor, Busch re-connected with agent Myron Selznick, whom Busch knew through his father, an executive who had worked for Myron's father Lewis in the teens and early twenties.

Myron Selznick soon secured work for Busch at Warner Bros. Pictures, and Busch decamped to Los Angeles to write his first film, Howard Hawks's The Crowd Roars. One of four writers on the production, Busch's name was misspelled in the credits.

Through the rest of the thirties, Busch worked for most of the major Hollywood studios, scripting mostly B-movies like The Big Shakedown. In 1938 he was nominated for an Academy Award for In Old Chicago, which was based on his story We the O'Learys, but failed to win. In 1940 he co-wrote The Westerner for director William Wyler and producer Samuel Goldwyn. Soon thereafter he went to work as Goldwyn's story editor, recommending Pride of the Yankees, in which Gary Cooper and Busch's soon-to-be wife Teresa Wright co-starred.

Settling in the hills of Encino with his growing family, Busch began writing novels. The Carrington Incident, published in 1941, was followed by the best-seller Duel in the Sun, which Lewis Selznick's other son David purchased and turned into the 1946 blockbuster of the same title. He now alternated between the writing of screenplays and novels, most of which became best-sellers. They Dream of Home, a tale of returning veterans, was followed by The Furies (1950). His most notable film of the period...for which Busch wrote the original screenplay...was Pursued starring Robert Mitchum and Teresa Wright, one of the first psychological Westerns with "noir" overtones. Around the same time, Busch also adapted the noir thriller The Postman Always Rings Twice (1946), for Metro-Goldwyn-Mayer.

In the early fifties, Busch and Wright divorced, and Busch left Hollywood for northern California, where he devoted himself to cattle ranching and the full-time writing of novels. There he would meet his wife-to-be Carmencita Baker and later Suzanne de Sanz.

Before Busch's final novel The Titan Game he had become one of San Francisco's leading literary lights and a Regent's Professor at the University of California.

Busch died from congestive heart failure in 1991 at the age of eighty-eight.

• Niven Busch's California Street Papers, 1955-59 (0.5 linear ft.) are housed in the Department of Special Collections and University Archives at Stanford University Libraries
• Niven Busch's The Gentleman from California Papers, 1964-66 (1 linear ft.) are housed in the Department of Special Collections and University Archives at Stanford University Libraries
• Niven Busch's The San Franciscans Papers, 1959-1962 (0.5 linear ft.) are housed in the Department of Special Collections and University Archives at Stanford University Libraries

Niven Busch