He played college football for the Alabama Crimson Tide, where he was twice recognized as an All-American, and was a member of two BCS National Championship teams.

He was selected as a strong safety by the Tampa Bay Buccaneers in the first round of the 2012 NFL draft, where he played for two and a half seasons before being traded to the St. Louis Rams in 2014, where he moved to the linebacker position.

In addition to playing football, Barron also competed in track & field, where he won multiple 5A individual state titles in events ranging from the shot put to the long jump during the 2008 season.

[9] During his sophomore season in 2009, Barron took over as a starter at safety and was second on Alabama's national championship team with 74 tackles and a Southeastern Conference-leading seven interceptions and a touchdown.

[22] Barron attended the NFL Combine in Indianapolis, but did not perform drills as he was still recovering after recently undergoing sports hernia surgery.

At the conclusion of the pre-draft process, Barron was projected to be a first round pick by NFL draft experts and scouts.

[33] He is the highest selected Alabama defensive back in school history, surpassing Antonio Langham, who was chosen ninth overall in 1994 by the Cleveland Browns.

In Week 3 of the preseason, Barron intercepted Tom Brady and ran the pick back for his first career NFL touchdown.

[35] He made his professional regular season debut in the Buccaneers' season-opening victory over the Carolina Panthers and finished the game with three solo tackles and two pass deflections.

[36] The next game, Barron made a season-high ten combined tackles and two pass deflections in a 41–34 loss at the New York Giants.

[37] In Week 4, Barron made eight combined tackles and forced his first career fumble in a 24–22 loss to the Washington Redskins.

[41] Barron returned as the Buccaneers' strong safety to begin his second season under coach Greg Schiano.

[43] The following week, Barron collected a career-high 13 combined tackles, of which ten were solo, a pass deflection, and made his first career sack on Drew Brees during a 16–14 loss to the New Orleans Saints.

[44] During a Week 3 loss to the New England Patriots, Barron finished with 11 combined tackles, was credited with half a sack, and intercepted Tom Brady for his first pick of the season.

[48] Barron finished his second season with 88 combined tackles, six pass deflections, two sacks, and two interceptions while starting in 14 games.

[50] Under new head coach Lovie Smith, Barron remained as the Buccaneers' starting strong safety to begin his third season.

Barron finished his career with the Buccaneers with 225 combined tackles, 18 pass deflections, three interceptions, two sacks, and a forced fumble while starting 38 games in three seasons.

[57] The next game, he racked up five solo tackles and sacked Arizona Cardinals backup quarterback Drew Stanton during a 31–14 loss.

[61] Barron entered his first training camp with the St. Louis Rams competing with veteran T. J. McDonald to be the starting strong safety.

[63] On October 11, 2015, he received his first start of the season during the Rams' 24–10 loss to the Green Bay Packers and made five combined tackles.

[64] The following week, Barron made his first career start at weakside linebacker after Alec Ogletree suffered a broken fibulia[65] He finished the 24–6 victory over the Cleveland Browns with a career-high 16 combined tackles.

[72] He started the Rams' season-opening game against the San Francisco 49ers, finishing the 28–0 loss with three combined tackles and two deflected passes.

[74] In Week 3 win over the Tampa Bay Buccaneers, he racked up nine combined tackles and intercepted quarterback Jameis Winston for his first pick as a Ram.

[75] The following week, Barron made eight solo tackles an intercepted Carson Palmer, helping the Rams defeat the Arizona Cardinals 24–22.

[85] On January 6, 2018, Barron started in his first career playoff game and recorded ten combined tackles (eight solo) in a 26–13 loss to the Atlanta Falcons in the Wild Card Round.

[95] In Week 4 against the Cincinnati Bengals, Barron recorded a team high 11 tackles and intercepted Andy Dalton in the 27–3 win.