Born in Bruceton, Tennessee, Willis attended Hollow Rock-Bruceton Central High School, where he was a two-time All-State selection, Regional Most Valuable Player, and West Tennessee Player of the Year. He earned four letters in football and basketball, and three in baseball. Willis was also the first person in Tennessee state history to be nominated for both the Mr Football Award for a Lineman (as a linebacker) and the Mr Football Award for a Back (as a tailback) in the same season.
Willis played college football for the University of Mississippi and received consensus All-American honors. During Willis’s senior season at Ole Miss, he received the Butkus Award and the Jack Lambert Award as the nation’s top linebacker.
Willis was drafted by the San Francisco 49ers in the first round of the 2007 NFL Draft. He played his entire eight-year career with the 49ers. As a member of the 49ers, Willis led the NFL in tackles, earned first-team All-Pro and Pro Bowl honors while being named the 2007 AP NFL Defensive Rookie of the Year. Willis made the Pro Bowl in his first seven seasons in the NFL, and earned All-Pro honors in his first six years.
Willis retired from football in March of 2015.