Frank Riley Castleman (March 17, 1877 – October 9, 1946) was an American football and baseball player, track athlete, and coach in multiple sports.

He competed for the United States in the 200 metre hurdles at the 1904 Summer Olympics held in St. Louis, Missouri, where he won the silver medal.

Castleman graduated from Colgate University in 1906, where he competed in football, baseball, and track and field.

[2][3] Castleman served as the head football coach at the University of Colorado at Boulder in 1906 and 1907, compiling a record of 7–6–4.

Castleman died at his home in Columbus, Ohio, on October 9, 1946, at the age of 69.