A lineal champion is a world championship title held initially by the winner of a fight between a divisions leading boxers. The concept of a lineal champion was developed by boxing fans who were dissatisfied with the tendency of various sanctioning bodies to recognize different champions and strip a champion of their title for refusing to fight its top-ranked contender. The term "lineal" refers to the manner in which titles in prize fighting traditionally passed from one champion to the next via contests in the ring, commonly described as "the man who beat the man". The lineal championship is simply the traditional world championship, and the adjective "lineal" in "Lineal World Champion" is only used to differentiate it from the growing number of Alphabet Soup "world champions".

The lineal championship is a notional title tracked by fans, and there is no money or organization to arrange a box-off to fill a vacant title, and there may not be consensus on who the top contenders are. The Lineal Boxing Champion (LBC) recognizes lineal championship vacancies, which are filled by the winner of a fight between the #1 and #2 contenders, or in rare instances, a... A Lineal Champion can lose his Lineal Championship if he dies, formally announces his retirement, is defeated in a Championship fight or formally declares that he is leaving his weight class to stay in another weight division.

Many boxing experts view the lineal championship as a prestigious status that trumps the world titles being issued by the sanctioning bodies. However, there are criticisms of the lineal championship, such as a fighter defending it against inferior opponents. Since the modern lineal championship is a notional title tracked by fans, there is no regulatory body in place that can force a champion to make defenses of their title against deserving opposition.