Ralph L. "Izzy" Isselhardt (January 13, 1910 – October 24, 1972) was an American professional football player who played in the National Football League (NFL) for the Detroit Lions and Cleveland Rams.

[3] Isselhardt signed a contract to play with the Lions for the 1936 season early in March of that year.

[4] Known as "Izzy" to his teammates,[5] Isselhardt played in one game for the Detroit Lions in 1936, before being assigned to a minor league farm club for additional experience.

[6] Isselhardt signed with the Cleveland Rams for the 1937 season[6] and saw action in eight games for the team.

[7] Isselhardt died October 24, 1972, at Grand Rapids, Michigan.