Malcolm M. MacArthur (January 19, 1862 – October 18, 1932) was a Scottish professional baseball player, who played for the Indianapolis Hoosiers of the American Association from May 2, 1884, to June 9, 1884. He was born in Glasgow, Scotland, and is one of only nine individuals in Major League Baseball history to be a Scottish native. MacArthur was a starting pitcher for six games with the Hoosiers, completed each game, and had a win–loss record of 1–5 in 52 innings pitched. In those six starts, he gave up 49 runs, 29 of them were earned, on 57 hits, and had 21 walks, and hit two batsmen. He had his only major league victory, and 8–2 defeat of the Louisville Colonels on May 9 at Eclipse Park in Louisville, Kentucky.