Defensive Rookie of the Year in 2007, he has been one of the league's most dominant linebackers. Willis became the first player in 49ers history to be selected as an All-Pro in each of his first six seasons (First Team - 2007, 2009-12; Second Team - 2008).

Willis was the first 49er since safety Ronnie Lott to be selected to the Pro Bowl in each of his first four seasons. He also became the first player in franchise history to be selected to the Pro Bowl in each of his first seven seasons. Willis joined linebacker Lawrence Taylor and linebacker Derrick Thomas as the only defensive players, since the merger in 1970, to be selected to the Pro Bowl in each of their first seven seasons.

A two-time recipient of the Bill Walsh Award, which is voted on by the coaches and awarded to the team's Most Valuable Player, Willis has earned the respect of the men he has played alongside and against. Along with defensive tackle Justin Smith and running back Frank Gore, the three are the only two-time winners of the award in team history.

Willis started all 112 games in which he appeared and registered 1,225 tackles, 20.5 sacks, eight interceptions (returning two for touchdowns), 16 forced fumbles, five fumble recoveries and 53 passes defensed. Since 2007, he is the only player in the NFL with at least 20.0 sacks (20.5), 15 forced fumbles (16) and eight interceptions (eight). Willis also started all eight playoff games and registered 84 tackles, 2.0 sacks, one interception, one fumble recovery and two passes defensed.