Barrett started playing college football at Nebraska-Omaha in 2010. After the school eliminated its football program, he transferred to Colorado State. Since Barrett was transferring from a school that cut its program, he was eligible to play immediately instead of having to sit out a year. Barrett played three seasons for Colorado State University. He started 35-of-38 games for CSU and totaled 246 tackles, 18 sacks, 32.5 tackles for a loss, three interceptions, six passes defended, seven forced fumbles, four fumble recoveries, and three blocked kicks. Barrett was named Mountain West ConferenceDefensive Player of the Year as a senior in 2013 after ranking fifth in the nation with 12 sacks and 20.5 tackles for a loss.
Professional career
Denver Broncos
2014 season: Rookie year
After going undrafted in the 2014 NFL Draft, Barrett signed with the Denver Broncos on May 16, 2014. After being waived for final roster cuts before the start of the 2014 season, the Broncos signed him to their practice squad on September 1, 2014. Barrett spent 16 weeks of the regular season competing on the practice squad, but was signed to the 53-man roster for the Week 7 game vs. the San Francisco 49ers. He was once again signed to the 53-man roster for the AFC Divisional Playoff Game vs. the Indianapolis Colts, but did not play.
2015 season
After finishing the 2015 NFL preseason with the most sacks of any player on the team, Barrett made the final 53-man roster. Barrett saw action in all 16 games and three postseason games, posting 41 tackles, 5.5 sacks, four passes defensed, four forced fumbles, two fumble recoveries, and nine special-teams tackles. Barrett tallied two tackles and one special-teams stop in Denver's three postseason games. He made one tackle and one special-teams stop in his NFL debut vs. the Baltimore Ravens on September 13, 2015. In Week 6 of the 2015 season, Barrett made his first NFL start vs. the Cleveland Browns after DeMarcus Ware suffered a back injury. He finished with nine tackles, 1.5 sacks, three tackles for loss, one pass defensed, one forced fumble, and one fumble recovery. On February 7, 2016, Barrett played in Super Bowl 50, but left the game to be evaluated with a concussion. He returned to finish the game and the Broncos defeated the Carolina Panthers by a score of 24–10.
2016 season
Barrett played all 16 games and totaled 31 tackles, 1.5 sacks, one forced fumble, and two passes defensed in addition to five special-teams stops.
2017 season
In 2017, Barrett appeared in 16 games, totaling 36 tackles, four sacks, two forced fumbles, one fumble recovery, and one blocked punt.
2018 season
On March 12, 2018, the Broncos placed a second-round restricted free agent tender on Barrett. On April 23, 2018, he signed his exclusive rights tender.
Tampa Bay Buccaneers
On March 15, 2019, Barrett signed a one-year contract with the Tampa Bay Buccaneers.
2019 season
During Week 2 against the Carolina Panthers, Barrett sacked Cam Newton a then career-best 3 times as the Buccaneers won 20–14. With his strong performance, he earned NFC Defensive Player of the Week. In the next game against the New York Giants, Barrett recorded a career-best 4 sacks and 2 forced fumbles, tying the franchise single-game sack record held by Simeon Rice and Marcus Jones, as well as becoming the first player in franchise history to record at least 3 sacks in back to back games. The Buccaneers narrowly lost 32–31. The following week, Barrett recorded his first NFL interception and a strip-sack on Jared Goff which was returned for a touchdown by teammate Ndamukong Suh in a 55–40 road victory over the Los Angeles Rams. As a result of his strong first month of play, he was named the NFC Defensive Player of the Month for September. In Week 15, during a 38–17 road victory over the Detroit Lions, Barrett recorded 5 tackles and a sack, tying the Buccaneers franchise record for sacks in a single season held by Warren Sapp. On December 17, 2019, Barrett was selected to the 2020 Pro Bowl, the first of his career. In Week 17, during a 28–22 overtime loss to the Atlanta Falcons, Barrett sacked Matt Ryan 3 times, breaking the Buccaneers franchise record set by Warren Sapp for the most sacks in a single season with 19.5. Barrett finished the 2019 season setting new career highs with a league leading 19.5 sacks, 58 tackles, 6 forced fumbles, 2 pass deflections, and 1 interception.
2020 season
On March 16, 2020, the Buccaneers placed the franchise tag on Barrett. He signed the one-year tender on July 15, 2020.
NFL statistics
Regular season
Postseason
NFL records
Most sacks through the first 3 weeks of a season - 8
Most sacks through the first 4 weeks of a season - 9
