The 1938 Iowa State Cyclones football team represented Iowa State College of Agricultural and Mechanic Arts (later renamed Iowa State University) in the Big Six Conference during the 1938 college football season. In their second season under head coach James J. Yeager, the Cyclones compiled a 7–1–1 record (3–1–1 against conference opponents), finished in second place in the conference, and outscored their opponents by a combined total of 125 to 64. They played their home games at Clyde Williams Field in Ames, Iowa.