In 1944, Scott married the actress Patricia Stillman, who was 21 years his junior. In 1950, they adopted two children, Sandra and Christopher.
Although Scott achieved fame as a motion picture actor, he managed to keep a fairly low profile with his private life. Offscreen he was a good friend of Fred Astaire and Cary Grant. He met Grant on the set of Hot Saturday (1932), and shortly afterwards, they moved in together and shared a beach house for 12 years in Malibu that became known as "Bachelor Hall". In 1944, Scott and Grant stopped living together, but they remained close friends for the rest of their lives.
Randolph Scott was an active Republican. In 1944, he attended the massive rally organized by David O. Selznick in the Los Angeles Coliseum in support of the Dewey-Bricker ticket as well as Governor Earl Warren of California, who would become Dewey's running mate in 1948. The gathering drew 93,000, with Cecil B. DeMille as the master of ceremonies and short speeches by Hedda Hopper and Walt Disney. Among those in attendance were Ann Sothern, Ginger Rogers, Adolphe Menjou, and Gary Cooper. Scott also supported Barry Goldwater in the 1964 United States presidential election.