Matthew Kiichi Heafy (born January 26, 1986) is a Japanese-born American musician best known as the guitarist and lead vocalist for the American heavy metal band Trivium. Heafy is also the lead vocalist for the band Capharnaum, along with Trivium's former producer Jason Suecof. He is also a gamer and practitioner of Brazilian Jiu-Jitsu, and he does daily live streams on his Twitch channel "matthewkheafy", which consist of playing video games, running guitar clinics, vocal warm ups, showcasing his Brazilian jiu-jitsu classes, and playing Trivium songs and acoustic covers.
Heafy was born in Iwakuni, Japan to a Japanese mother and an American father. His father, formerly a member of the United States Marine Corps, is half Irish and half German. Although Heafy was born in Japan, and is Japanese, he only lived there for one year and does not speak Japanese fluently; however, he uses some basic phrases when he performs in Japan. His family then moved to Orlando, Florida, where he currently resides. Heafy attended Lake Brantley High School. He completed his senior year while also touring in Europe, and graduated in 2004. During those years, Heafy used to live a straight edge lifestyle. Heafy also has a younger sister who does covers of video game music on her YouTube channel.