Katsunari Takayama (?? ??, Takayama Katsunari, born May 12, 1983) is a Japanese former professional boxer who competed from 2000 to 2016.
He is a five-time minimumweight world champion, having held the WBC title in 2005, the IBF title twice between 2013 and 2015, and the WBO title twice between 2014 and 2017.
He also held the WBA interim title from to 2006 to 2007.
He retired from professional boxing in April 2017, as WBO world champion, to focus on participation in the 2020 Olympics.