After he graduated from Warren High School in Arkansas, where he played football as a wide receiver, Gragg committed to the University of Arkansas along with three other Warren players. Although he spent his freshman season as a receiver on the Arkansas Razorbacks football squad, the coaching staff converted Gragg into a tight end in 2010. In his sophomore and junior seasons, the Razorbacks made appearances in Bowl Championship Series games and defeated the Kansas State Wildcats in the 2012 Cotton Bowl Classic, which culminated the 2011 season. A knee injury caused Gragg to miss eight games in his senior season as the Arkansas team finished with a losing record. Invited to participate in the NFL Scouting Combine, an evaluative competition among prospective NFL players, Gragg ran the fastest 40-yard dash time and had the second-highest vertical jump among tight ends in attendance; in the draft, the Bills chose Gragg with the 222nd overall selection, a pick Buffalo acquired from a trade with the St. Louis Rams. One of five tight ends in spring training, he made Buffalo's regular-season roster and played in nine regular-season games during the 2013 NFL season. He then played in 10 games in 2014 and 13 games in 2015 before missing the entire 2016 season due to injury.
Chris Gragg was born on June 30, 1990, in Pine Bluff, Arkansas, to Kelvin and Tenita Gragg, both of whom worked as educators. Kelvin coached the Warren High School football team, and Chris served as the team's water boy until he was in junior high school. For the Warren squad, Gragg played football as a wide receiver alongside future NFL players Jarius Wright and Greg Childs. During his senior year, Gragg accumulated 420 receiving yards and caught 8 touchdowns. Recruiting website Rivals.com evaluated him as a 2-star prospect on a 1–5 star scale and ranked Gragg as the 15th best player in Arkansas at his position, while Scout.com ranked him as the 148th best receiver in the nation. In July 2007, Gragg committed to the University of Arkansas, as did three other players from Warren.
In his freshman season, Gragg played in all 12 of the Arkansas Razorbacks' games as the team finished with a 5–7 win–loss record. During the second game of the season, against the Louisiana–Monroe Warhawks, Gragg caught a 25-yard pass from quarterback Casey Dick on fourth down and one to continue a drive that ended with the game-winning touchdown. The catch was Gragg's only reception in 2008. After he dislocated his ankle in a preseason practice, he was given a medical redshirt and did not play for the 2009 season.
In 2010, Gragg was converted into a tight end, which made three slots at the position on the Razorbacks' depth chart. Garrick McGee, the offensive coordinator for the team, observed that "he's a really big receiver in a tight end body", and expected opponents to have "matchup problem[s]" against Gragg. When Arkansas faced the Georgia Bulldogs on September 18, Gragg caught a touchdown from a 57-yard pass for his first reception of the year. The 2010 Arkansas Razorbacks ended the year with a 10–3 record, and were invited to play in the Sugar Bowl against the Ohio State Buckeyes, a game that Arkansas lost 31–26 after Ohio State defensive end Solomon Thomas intercepted a pass from quarterback Ryan Mallett in the final minute of the game. Gragg made one catch in the contest for 16 yards; he finished the year with 8 receptions for 171 yards and two touchdowns.
Prior to the 2011 season, a writer for Arkansas Business predicted that Gragg "will figure prominently into the offense if he improves his blocking": Gragg replaced D. J. Williams, the first-string tight end who graduated in 2010. In the Razorbacks' eleventh game of the season, Gragg caught 8 passes for 119 yards, both single-game career highs, as the team defeated the Mississippi State Bulldogs and moved to a 10–1 record. The Bowl Championship Series (BCS) system subsequently ranked Arkansas as the third-best team in the nation, behind the Louisiana State University Tigers and the Alabama Crimson Tide, with the former scheduled as the Razorbacks' next opponent. Brett Martel of Associated Press stated that the November 25 matchup, a part of the Arkansas–LSU football rivalry, "could be even more important than the so-called 'Game of the Century'" between the Tigers and the Crimson Tide earlier in the year, as both teams in the rivalry competed for a position in the BCS National Championship Game. Though Arkansas opened with a 14–0 lead, the Tigers regained the lead by halftime and won, 41–17. Out of contention for the National Championship Game, the team finished the year ranked sixth in the BCS standings and were invited to play in the 2012 Cotton Bowl Classic, where they defeated the Kansas State Wildcats 29–16: with the victory, Arkansas tied a team record for most wins in a season. Over the season, Gragg caught 41 receptions, third most on the team, for 518 yards and two touchdowns.
In July 2012, Gragg was listed as a preseason nominee for the John Mackey Award, a recognition presented annually by the Nassau County Sports Commission to the best tight end in college football. Though voted to the second-team of the Coaches Preseason All-Southeastern Conference (SEC) squad, an honorific roster composed of the second-best players in the SEC, ESPN writers Edward Aschoff and Chris Low ranked Gragg as the best tight end in the conference. In Arkansas' season opener against the Jacksonville State Gamecocks, Gragg accumulated 110 yards and two touchdowns over 7 catches, a performance for which he earned the John Mackey Tight End of the Week award. On September 9, Gragg suffered a bone bruise in his knee against the Rutgers Scarlet Knights which caused him to miss the next three games; upon return, Gragg reaggravated the injury and missed the rest of the season's matches. He finished his final season at Arkansas with 22 receptions for 289 yards and three touchdowns, while the team ended with a 4–8 record; academically, he graduated with a degree in sports management. After his senior year, Gragg participated in the NFL Scouting Combine, where he ran the fastest 40-yard dash time, the third-fastest 3 cone drill, had the third-longest broad jump, and the second-highest vertical jump of all tight ends in attendance. In an overview of his Combine performance, a writer for the NFL praised his speed and "receiver-like hands", but criticized him for a lack of agility and occasional dropped passes. The writer compared Gragg to tight end Daniel Fells.
The Buffalo Bills selected Gragg with the 222nd overall selection in the 2013 NFL Draft, a slot they obtained from a trade with the St. Louis Rams. When he was drafted, Gragg became the second tight end Buffalo had ever selected out of Arkansas, and the first Arkansas player to be selected by the Bills since 1973. Gragg was the first rookie out of the 2013 Bills' draft class to sign a contract. In preseason practice, Gragg was one of five tight ends on the Buffalo team as he tried to earn one of the 53 positions available on the active roster. While the team trained at St. John Fisher College, Buffalo head coach Doug Marrone praised Gragg for his knowledge of the Bills' playbook and his vertical running speed. In four preseason games, he totaled 5 receptions for 38 yards. When the Bills cut their roster to 53 players, Gragg made the team; on an "A–F" scale, ESPN columnist Mike Rodak gave the Bills a "C" grade in tight end depth and stated that Gragg "would be in the bottom 10 percent of NFL starters at [the position]". Gragg made his regular season NFL debut on October 13 against the Cincinnati Bengals, and caught his first career reception and touchdown against the Pittsburgh Steelers four games later. When Buffalo faced the Tampa Bay Buccaneers on December 8, Gragg started in a game for the first time during the regular season. By the end of 2013, Gragg caught 5 receptions for 53 yards and a touchdown in nine career games played. Collectively, the Bills finished last in the AFC East with a 6–10 record.
Prior to the Bills' 2014 training camp, Rodak gave Gragg a "45%" chance to make Buffalo's 53-man roster: Rodak described him as "the most athletic tight end" with the Bills, but also wrote that "there might not be a spot for Gragg" with tight ends Tony Moeaki, Scott Chandler, and Lee Smith on the team as well. During the preseason, Gragg was hospitalized with heat cramps, but returned to practice on July 30. The Bills faced the New York Giants in their first preseason game, a Pro Football Hall of Fame Game, and according to Jay Skurski of The Buffalo News, Gragg "[had] a chance to impress" with Moeaki and Chandler injured and unable to play: in the game, Gragg had 4 catches for 24 yards and a fumble. He finished the preseason with 10 receptions for 66 yards, and made the regular season roster. In the fourth quarter of the Bills' October 5 matchup against the Detroit Lions, Gragg caught a touchdown pass that, with an added two-point conversion, tied the game; Buffalo won the contest, 17–14, and moved to a 3–2 record. When he attempted to catch a low-thrown pass in the second half of a game against the New York Jets on November 24, Gragg injured his right knee, which caused him to miss the remainder of the Bills' season. During 2014, over the ten games in which he played, Gragg accumulated 7 receptions for 53 yards and a touchdown as Buffalo finished with a 9–7 record, second in the AFC East behind the New England Patriots.
Gragg played in 13 games, starting 4, in 2015, catching 12 passes for 150 yards and no touchdowns. On August 26, 2016, Gragg suffered a torn ACL in a preseason game against the Washington Redskins that ended up sidelining him for the entire 2016 season. He became a free agent in March 2017.
On July 28, 2017, Gragg signed with the New York Jets. He was placed on injured reserve on September 1, 2017, after suffering an ankle injury.
Chris's brother, Will, also plays football as a tight end: Will said that Chris taught him how to catch, and that when Chris learned something new in Buffalo or at Arkansas, Chris taught it to him. Will transferred to Dumas High School when Kelvin accepted a position as the superintendent of the school district. Will, who received offers from forty-five collegiate schools, committed to the University of Arkansas in September 2014 and signed with the institution in December.