Professional boxing is divided into 17 weight classes recognised by the four major sanctioning bodies (WBC, WBA, IBF, and WBO). Weight divisions exist to ensure fair competition by matching fighters of similar size. Each division has an upper weight limit that a fighter must make at the official weigh-in, typically held the day before the bout. Fighters who fail to make weight may be fined, stripped of title eligibility, or have the bout cancelled entirely.
The table below lists every division from lightest to heaviest, including the weight limit in both pounds and kilograms, along with notable champions who have held titles in that class.