John Phalen "Stuffy" McInnis (September 19, 1890 – February 16, 1960) was a first baseman and manager in Major League Baseball. McInnis gained his nickname as a youngster in the Boston suburban leagues, where his spectacular playing brought shouts of "that's the stuff, kid". From 1909 to 1927, McInnis played for the Philadelphia Athletics (1909–1917), Boston Red Sox (1918–1921), Cleveland Indians (1922), Boston Braves (1923–1924), Pittsburgh Pirates (1925–1926) and Philadelphia Phillies (1927). He batted and threw right-handed.