Credited as the greatest Lightweight combatant in mixed martial arts history, Penn's domination of the division, as well as his performances in higher weight classes have him regarded as one of the greatest fighters in the history of the sport.
Kreditteret som den største letvægts-kæmper i MMA's historie, har Penns dominering i divisionen, såvel som sine præstationer i højre vægtklasser anset ham for at være en af de største kæmpere i sportens historie.