Quinn attended Fort Dorchester High School in North Charleston, South Carolina, where he played for the Fort Dorchester Patriots high school football team. As a senior, his season was shortened after undergoing brain surgery for a benign tumor. Quinn made a full recovery and was able to resume his football career. He registered 54 tackles, 10 tackles for loss, 5 sacks and 21 quarterback hurries before the surgery. He was ranked the 19th best defensive end recruit by Scout.com and the 18th by Rivals.com He was also a 3-time heavyweight state champ in 4A wrestling. He also played in the 2008 U.S. Army All-American Bowl.
College career
Quinn attended the University of North Carolina at Chapel Hill, where he played for the North Carolina Tar Heels football team. As a freshman in 2008, Quinn started 12 of 13 games, recording 34 tackles and two quarterback sacks and forced two fumbles. He was also named the ACC's Brian Piccolo Award winner as the league's most courageous player and finished third in the voting for the ACC Defensive Rookie of the Year honors. As a sophomore in 2009, Quinn had 52 tackles and led the ACC and was 15th in the country in tackles for losses with 19.0 and was second in the league and 16th in the nation in sacks with 11.0 sacks. Additionally, he had three pass breakups and was second in the ACC and fourth in the country with six forced fumbles. For his efforts, he was a First-team All-ACC selection and was a Second-team All-American by CBS. He also finished second in the ACC Defensive Player of the Year voting. As a junior in 2010, Quinn missed the season after he was ruled ineligible by the NCAA for lying to investigators about receiving travel accommodations and jewelry. On November 19, 2013, the University of North Carolina sent a permanent disassociation letter to Quinn, Marvin Austin, and Greg Little for the improper benefits taken during their time at the university. The three athletes are prohibited from contacting current North Carolina athletes and are not allowed inside the Kenan Football Center or other athletic facilities on campus.
Professional career
Already in April 2010, Quinn was regarded as one of the top prospects for the 2011 NFL Draft. Despite sitting out all of his junior season, he was still projected to be a top-10 selection in January 2011. His stock slightly dropped after the combine, projecting him at No. 11 in early March.
Quinn was drafted in the first round as the 14th overall pick in the 2011 NFL Draft by the St. Louis Rams. On July 30, 2011, he signed a four-year $9.4 million contract with the Rams and arrived a day late to practice due to the birth of his first son. On September 19, 2011, Quinn recorded his first career sack against the Giants on Monday Night Football. On October 30, 2011, he recorded his second sack and blocked a punt against the New Orleans Saints, earning the NFC Special Teams Player of the Week Award for his effort. Quinn ended his rookie season with five sacks, three blocked punts, and generated positive reviews for his pass rushing skills. In 2012, Quinn started fourteen of the Rams' sixteen games. He set career highs in tackles and sacks with 29 and 10.5, respectively. In Week 5 against the Arizona Cardinals, he recorded 3 sacks, a pass deflection, and the first forced fumble of his career. In Week 1 of 2013 versus the Arizona Cardinals, Quinn tied his career high for sacks in a game with three, causing two fumbles and was also held once by Cardinal left tackle Levi Brown in a 27–24 Rams win in St. Louis. For his efforts, he was named Sports Illustrated's NFC Defensive Player of the Weekfor the first time. In addition he was named the Official NFL NFC Defensive Player of the Week on September 11, 2013. In Week 11, Quinn forced a fumble that was recovered for a touchdown by Chris Long and for their efforts they were named co-Sports Illustrated's NFC Defensive Players of the Week. In Week 16, Quinn recorded 3 sacks against the Tampa Bay Buccaneers, passing Kevin Carter for the most sacks in a single season by a Ram with 18. Quinn was awarded the 2013 PFWA Defensive Player of the Year award; in addition to being a consensus First-team All-Pro. On September 13, 2014, Quinn signed a six-year extension with the Rams through the 2019 season. On December 15, 2016, Quinn was placed on injured reserve with a concussion.
On March 14, 2018, Quinn was traded to the Miami Dolphins in exchange for a 2018 fourth-round draft pick and a swap of sixth-round picks. He started all 16 games, finishing with a team-leading 6.5 sacks, along with 38 combined tackles and two forced fumbles.
On March 28, 2019, Quinn was traded to the Dallas Cowboys in exchange for a 2020 sixth-round pick. Because the number 94 is currently worn by Randy Gregory, Quinn wears number 58 for the Cowboys. On August 8, 2019, the league announced that Quinn was suspended the first two games of the 2019 season for a violation of the league’s policy on performance-enhancing substances, which he stated was related to his anti-seizure medication. He was reinstated from suspension on September 16, and the Cowboys were given a roster exemption for him. In week 4 against the New Orleans Saints, Quinn sacked Teddy Bridgewater twice in the 12-10 loss. In week 6 against the New York Jets, Quinn sacked Sam Darnold twice in the 24-22 loss. In week 7 against the Philadelphia Eagles, Quinn recorded a sack on Carson Wentz before leaving the game with a rib injury. Without Quinn, the Cowboys won 37-10.
Chicago Bears
On April 1, 2020, Quinn signed a five-year, $70 million contract with the Chicago Bears.
