Wheeler Roger "Doc" Johnston (September 9, 1887 – February 17, 1961) was an American professional baseball first baseman.

During eleven seasons in the major leagues, Johnston played for the Cincinnati Reds, Cleveland Indians, Pittsburgh Pirates, and Philadelphia Athletics.

His brother Jimmy Johnston was also a major league player.

It marked the first World Series and first Big Four championship to feature two brothers on opposing teams.

This biographical article relating to an American baseball infielder is a stub.