Williams was originally recruited by University of Hawaii coaches and offered a scholarship to play for the Hawaii Warriors football team after a Warriors scout saw him play during the Australian National Championships. He verbally committed to play for Hawaii when he was 16 years old; however, the NCAA clearing house said he was missing a mathematics and an English class and would not be able to enroll for the 2009 season. Williams later chose to enroll at Arizona Western College, after coaches saw him play in an exhibition against New Zealand while they were teaching at a football clinic. At the time, Williams was the first Indigenous Australian to receive a scholarship to play college football in the United States. At Western, Williams developed into one of the highest rated recruits out of junior college for the 2011 class. After receiving scholarship offers to play from over 25 schools, Williams enrolled in the University of Alabama for the spring 2011 semester, and began practice with coach Nick Saban's Alabama Crimson Tide football team. Williams started all 13 games of the 2011 season with the Crimson Tide at defensive end, and he made 24 total tackles and half of a quarterback sack during the course of the year. During the offseason, Williams gained a degree of internet fame when images of him bench pressing were posted to his Twitter account. Prior to the start of the 2012 season, Williams was named to the preseason award watch lists for the Chuck Bednarik Award, the Lombardi Award, the Bronko Nagurski Trophy and the Outland Trophy. He was also named to the ESPN.com Preseason All-America Team at nose tackle. For the 2012 regular season, Williams was a starter for Alabama as the nose guard in 13 of the 14 games, and he made 37 total tackles, one quarterback sack and blocked a kick during the course of the year. In their 41–14 victory over the Michigan Wolverines to open the 2012 season, Williams suffered a concussion that kept him out of Alabama's week two matchup against WKU. He returned to the starting line-up for their week three game against Arkansas. In their 52–0 victory over the Razorbacks, Williams also played on offence for the first time in his Crimson Tide career when he lined up at the fullback position late in the second quarter on a one-yard Eddie Lacy touchdown run. In the SEC Championship game against Georgia he blocked for an Eddie Lacy touchdown run on the first play of the fourth quarter after sitting out the third quarter with a knee injury. After the season, the AP named Williams to the AP All-SEC Second Team.
Prior to the NFL Scouting Combine, Williams, who reportedly bench-pressed a maximum of, vowed to break the 225-pound bench press record of 51 repetitions, established by Justin Ernest in 1999. However, he eventually came well short, recording 30 reps. Predicted to be selected as high as late in the first round, Williams was taken in the fifth round of the 2013 NFL Draft with the 137th overall selection by the Seattle Seahawks.
Seattle Seahawks
Williams signed his initial rookie contract with Seattle on 10 May 2013. On 26 August 2013, Williams was placed on the injured reserve list for the 2013 season as the result of a knee injury that sidelined him for the entirety of his rookie season with Seattle. Through Week 16 of the regular season, Williams rehabbed his knee in his native Australia where he used Orthokine to help with joint pain associated with his knee injury. Although he did not play a down during the season due to his injury, Williams became the first Australian to win a Super Bowlring after Seattle's victory in Super Bowl XLVIII. On 1 August 2014, Williams was again placed on the injured reserve list for the 2014 season once again as the result of a knee injury. After not playing during the regular season for a second consecutive year due to injury, the Seahawks waived Williams on 6 March 2015. On 16 March 2015, Williams did an interview with The Courier-Mail in Brisbane, Australia. Williams said that he'd agreed to a new deal with the team and would return to Seattle in a couple of weeks. On 9 March 2016, Williams was waived by the Seahawks.
Personal life
In May 2015, Williams was diagnosed with papillary Type 2 cancer and had to undergo kidney surgery. In a statement through the Seahawks, Williams said, "Although disappointing, I am a fighter and will handle this. I am going to focus on my health and fighting this battle with a return to football as my ultimate goal". After football, Williams became a strength & conditioning coach.
