Guinn Terrell Williams Jr. (April 26, 1899 – June 6, 1962) was an American actor who appeared in memorable Westerns such as Dodge City (1939), Santa Fe Trail (1940), and The Comancheros (1961).

He was nicknamed "Big Boy" because he was 6' 2" and had a muscular build from years of working on ranches and playing semiprofessional and professional baseball.

[2] Williams made his screen debut in the 1919 comedy, Almost A Husband, with Will Rogers and Cullen Landis, was the titular leading man to singing comedienne Fannie Brice in My Man (1928), and was featured in a large supporting role in Frank Borzage's Lucky Star (1929) with Janet Gaynor and Charles Farrell.

From the late 1930s to the mid-1940s, Williams appeared in supporting roles in a number of A pictures, sometimes with high billing, such as You Only Live Once, and in Columbia's first Technicolor film, The Desperadoes (1943).

On television, he appeared in the Western series Gunsmoke as Groat, a gruff, bully cowboy in the 1957 episode "Skid Row" (S2E22).

Williams was interred in the Enduring Faith section at Forest Lawn Memorial Park, Hollywood Hills of Los Angeles.