The World Boxing Union (WBU) was a boxing sanctioning body. The original WBU was founded in January 1995 by IBF European representative, boxing journalist, actor and former holder of the title of Britain's heaviest man Jon W. Robinson. It sanctioned boxing with various promoters worldwide. Following Robinson's death in 2004, the organization became dormant and was eventually dissolved.

Pongsaklek Wonjongkam is a former Thai professional boxer and current boxing trainer. He is a two-time former lineal flyweight champion. During his first reign as world flyweight champion, which lasted between 2001 and 2007, Wonjongkam defended his title 17 times against 16 fighters, with both numbers being a flyweight record.