Roy Johnson (October 1, 1895 – January 10, 1986) was an American right-handed pitcher and longtime coach in Major League Baseball. He also was the interim manager of the Chicago Cubs for one game in 1944. He was nicknamed "Hardrock" as a minor league manager because his teams played in a tough, uncompromising way.
In 1935, Johnson was promoted to a coaching position with the Cubs by manager Charlie Grimm. He was associated with the Cubs for the remainder of his career as a coach (1935–39; 1944–53), minor league pilot, and scout. The Cubs won three National League pennants (1935, 1938 and 1945) during Johnson's 15 total years as a coach.
On May 3, 1944, with the Cubs having lost nine of their first ten National League games, he served as interim manager for one game, between Jimmie Wilson and Grimm's second term; Chicago lost to the Cincinnati Reds, 10–4, their tenth defeat in a row.