Ronald Jack Pennick was an American film actor. After working as a gold miner as a young man, serving as a U.S. Marine, he would go on to appear in more than 140 films between 1926 and 1962. Pennick was a leading member to in the informal John Ford Stock Company, appearing in dozens of the director's films. Pennick also drilled the military extras in John Wayne's The Alamo (1960).

The Alamo is a 1960 American epic historical war film about the 1836 Battle of the Alamo produced and directed by John Wayne and starring Wayne as Davy Crockett. The film also co-stars Richard Widmark as Jim Bowie and Laurence Harvey as William B. Travis, and features Frankie Avalon, Patrick Wayne, Linda Cristal, Joan O'Brien, Chill Wills, Joseph Calleia, Ken Curtis, Ruben Padilla as Santa Anna, and Richard Boone as Sam Houston. Shot in 70 mm Todd-AO by William H. Clothier, it was released by United Artists.