Rudolph Kallio (December 14, 1892 – April 6, 1979) was a pitcher in Major League Baseball who played for two different teams between 1918 and 1925.

Kallio entered the majors in 1918 with the Detroit Tigers, playing for them two years before joining the Boston Red Sox.

In his rookie season, he showed promise as a solid starter for Detroit, going 8-14 with 70 strikeouts and a 3.62 ERA in 181⅓ innings pitched.

In a three-year career, Kallio posted a 9-18 record with a 4.17 ERA in 49 appearances, including 27 starts, 10 complete games, two shutouts, one save, 75 strikeouts, and 222⅓ innings of work.

Following his playing career, Kallio worked as a coach and traveling secretary for the Portland Beavers (1943) and later scouted for the Chicago Cubs (1946).