He played college football for the Ohio State Buckeyes, where he earned All-American honors twice and won the Lombardi Award as a senior.

[1] He attended Centerville High School, where he was a teammate of former Cincinnati Bengals kicker Mike Nugent on the football team.

[1] He holds multiple defensive records and was one of three active NFL players who played for the Centerville Elks high school football team.

His performances earned him first-team All-Big Ten honors in all three years he started and the Most Valuable Player award for the Tostitos Fiesta Bowl.

Before the 2005 season for the Ohio State Buckeyes, Hawk, along with fellow starting linebackers Bobby Carpenter and Anthony Schlegel and center Nick Mangold, grew their hair out long to honor Pat Tillman.

Tillman turned down a National Football League (NFL) contract worth $3.6 million to join the Army in May 2002, after the outbreak of The War on Terror and was killed in action by friendly fire on April 22, 2004.

On September 24, 2006, Hawk recorded eight combined tackles (five solo) and made his first career sack on Detroit Lions quarterback Jon Kitna for a nine-yard loss during the fourth quarter.

On December 10, 2006, Hawk recorded five combined tackles (four solo), a pass deflection, and made his first career interception during a 30–19 win at the San Francisco 49ers in Week 14.

He intercepted a pass by 49ers' quarterback Alex Smith, that was originally intended for Vernon Davis, and returned it for a 25-yard gain during the fourth quarter.

Hawk started in all 16 games as a rookie in 2006 and finished the season with 119 combined tackles (82 solo), six pass deflections, 3.5 sacks, two interceptions, and a forced fumble.

The following week, Hawk made seven combined tackles (four solo) and one sack as the Packers lost 23–20 against the New York Giants in the NFC Championship Game.

He started in the Green Bay Packers' season-opening 24–19 victory against the Minnesota Vikings and collected a season-high ten combined tackles (seven solo).

[17] On January 19, 2009, the Green Bay Packers announced their decision to hire former New England Patriots' secondary coach Dom Capers.

[16] Hawk and Barnett retained their roles as the starting inside linebackers in 2010 and played alongside Clay Matthews III and Brad Jones.

Hawk intercepted a pass by Giants' quarterback Eli Manning, that was intended for running back Ahmad Bradshaw, during the fourth quarter.

On February 6, 2011, Hawk appeared in Super Bowl XLV with the Green Bay Packers and made five combined tackles (two solo) and deflected a pass as they defeated the Pittsburgh Steelers 31–25.

[24][25] Hawk retained his role as a starting inside linebacker, but played alongside Desmond Bishop after Nick Barnett was released.

[26] On November 24, 2011, Hawk recorded six combined tackles (four solo) and a pass deflection before exiting during halftime of the Packers' 27–15 victory at the Detroit Lions due to a calf injury.

He started in the Green Bay Packers' season-opener against the San Francisco 49ers and collected a career-high 14 combined tackles (ten solo) during their 30–22 loss.

[29] On October 13, 2013, Hawk made ten combined tackles (eight solo) and a career-high three sacks during a 19–17 victory at the Baltimore Ravens in Week 6.

[31] Hawk finished the 2013 NFL season with 118 combined tackles (74 solo), a career-high five sacks, five pass deflections, and one interception in 16 games and 16 starts.

[16] Hawk and Brad Jones returned as the starting inside linebacker duo in 2014 and played alongside Clay Matthews III and Julius Peppers.

He appeared in all 16 games in 2014 and had 13 starts while recording a total of 89 combined tackles (53 solo), two pass deflections, and was credited with half a sack.

Hawk managed to sack his future brother-in-law twice during the game and was co-Most Valuable Player (MVP) of the bowl, which ended with an Ohio State victory.