Oscar "Heavy" Johnson (1895–1960) was a baseball player in the Negro Leagues. He played catcher and outfielder. Johnson was one of the Negro League's foremost power hitters in the 1920s, reportedly weighing 250 pounds, and known for hitting home runs. Longtime MLB umpire Jocko Conlan once said that Johnson "could hit a ball out of any park."
Johnson was part of the all-black 25th Infantry Wreckers, a teammate of other future Negro Leaguers including Bullet Rogan, Lemuel Hawkins, and Dobie Moore. He briefly played for the St. Louis Giants in 1920 while on Army furlough, hitting .300 in 3 games, but did not join the Negro Leagues until his discharge in 1922. In his rookie season with the Kansas City Monarchs, Johnson batted .406, and posted a .345 average in the Cuban winter league. Johnson won a retroactive triple crown in 1923 with a .406 batting average, 20 home runs and 120 RBI in 98 games. Johnson was also the first member of the Monarchs to hit a home run at the new Kansas City Municipal Stadium. Johnson was credited with more than 60 home runs against all opposition in 1924, and batted .296 in the 1924 Colored World Series, which was won by the Monarchs. Johnson then moved to the Baltimore Black Sox, where he posted averages of .345 and .337 in his 2 seasons with the club. In 1927, with the Harrisburg Giants, Johnson hit .316, teaming with John Beckwith and Oscar Charleston. Johnson split the 1928 season between the Cleveland Tigers and the Memphis Red Sox, posting a .315 average overall.
Former pitcher Bill "Plunk" Drake said that Johnson was once sleeping on the bench when he was awoken and told to pinch-hit; he grabbed a fungo bat and hit a home run. Despite Johnson's weight, he was described as a "remarkably fast runner for his bulk." He was also described as temperamental and moody, one of the "nasty boys". Johnson finished his career in 1933 with a .337 lifetime batting average.