Undrafted in the NHL, Brown signed a two-year, entry level contract with the Tampa Bay Lightning on March 28, 2012.
Upon signing with Tampa Bay, Lightning General Manager Steve Yzerman said, "I'm anxious to see him play."
On March 31, 2012, Brown made his NHL debut in Tampa Bay's 3–2 overtime victory against the Winnipeg Jets.
On April 7, he recorded his first career NHL assist in a 4–3 overtime win, also coming against the Winnipeg Jets.

On September 9, 2012, the Tampa Bay Lightning assigned Brown, as well as 17 other players, to the Syracuse Crunch of the American Hockey League (AHL), their top minor league affiliate.
This was done in part due to the ongoing 2012–13 NHL lockout that cancelled the first half of the 2012–13 season until late January.
On December 28, 2012, Brown sustained a shoulder injury in a 4–2 Crunch victory over the Norfolk Admirals.
Prior to the injury, Brown had six goals, 17 points and four penalty minutes in 26 games for Syracuse.
It was revealed later in the day that Brown had suffered a broken collarbone, which required surgery to repair.
Although expected to compete for a roster spot with the Lightning once NHL play resumed, the injury was expected to sideline him for six-to-eight weeks.

On July 7, 2013, Tampa Bay announced that they had re-signed Brown to a one-year, two-way contract.
At the end of the season, Brown had skated in 51 games with the Crunch, recording 10 goals and 28 points to go along with 27 penalty minutes.
Additionally, he played in 18 Calder Cup playoff games with Syracuse, registering four goals and nine points to go along with 18 penalty minutes.

On September 29, 2013, Brown was reassigned to the Crunch by the Lightning as part of roster cuts for the upcoming 2013–14 season.
On November 11, 2013, however, Tampa Bay recalled Brown from Syracuse.
Prior to being recalled, Brown was on a two-game point streak, with a goal and an assist.
It was during this time that he received the nickname "Brownov" as the third player on a successful forward line with Russians Vladislav Namestnikov and Nikita Kucherov.

On November 16, 2013, Brown scored his first career NHL goal in a 6–3 loss to the Phoenix Coyotes.

On June 6, 2014, the Lightning announced the re-signing of forward Brown to a two-year, one-way contract.
He appeared in 63 games with the Lightning during the 2014–15 season, posting four goals and 19 points while averaging 13:02 in ice time per game.
Brown also played in all four Stanley Cup playoff games in 2014, notching two assists in Tampa Bay's four-game series defeat at the hands of the Montreal Canadiens in the Eastern Conference Quarter-finals.
During the post-season, Brown was averaging 14:59 minutes in ice time.

On May 3, 2015, Brown scored his first career Stanley Cup playoff goal in a 6–2 Lightning win over the Montreal Canadiens in the Eastern Conference Semi-finals.

On June 24, 2016, the Lightning announced the re-signing of Brown to two-year contract extension.
Brown played in 78 regular season games during the past season, recording eight goals and 22 points.
Brown was tied for third on the team with a plus-16 rating.
Brown set career bests in games played, goals, points, plus/minus and penalty minutes last season.
He also appeared in nine Stanley Cup Playoff games, recording two assists and two penalty minutes.
Brown has skated in 198 career NHL games, all with the Lightning over four seasons, registering 15 goals and 51 points.
He also has skated in 37 playoff games, recording a goal and six points.

On October 15, 2016, Brown skated in his 200th career NHL game, which came during a 3–2 Lightning win over the visiting New Jersey Devils.
Undrafted in the NHL, Brown signed a two-year, entry level contract with the Tampa Bay Lightning on March 28, 2012. Upon signing with Tampa Bay, Lightning General Manager Steve Yzerman said, "I'm anxious to see him play." On March 31, 2012, Brown made his NHL debut in Tampa Bay's 3–2 overtime victory against the Winnipeg Jets. On April 7, he recorded his first career NHL assist in a 4–3 overtime win, also coming against the Winnipeg Jets.
On September 9, 2012, the Tampa Bay Lightning assigned Brown, as well as 17 other players, to the Syracuse Crunch of the American Hockey League (AHL), their top minor league affiliate. This was done in part due to the ongoing 2012–13 NHL lockout that cancelled the first half of the 2012–13 season until late January. On December 28, 2012, Brown sustained a shoulder injury in a 4–2 Crunch victory over the Norfolk Admirals. Prior to the injury, Brown had six goals, 17 points and four penalty minutes in 26 games for Syracuse. It was revealed later in the day that Brown had suffered a broken collarbone, which required surgery to repair. Although expected to compete for a roster spot with the Lightning once NHL play resumed, the injury was expected to sideline him for six-to-eight weeks.
On July 7, 2013, Tampa Bay announced that they had re-signed Brown to a one-year, two-way contract. At the end of the season, Brown had skated in 51 games with the Crunch, recording 10 goals and 28 points to go along with 27 penalty minutes. Additionally, he played in 18 Calder Cup playoff games with Syracuse, registering four goals and nine points to go along with 18 penalty minutes.
On September 29, 2013, Brown was reassigned to the Crunch by the Lightning as part of roster cuts for the upcoming 2013–14 season. On November 11, 2013, however, Tampa Bay recalled Brown from Syracuse. Prior to being recalled, Brown was on a two-game point streak, with a goal and an assist. It was during this time that he received the nickname "Brownov" as the third player on a successful forward line with Russians Vladislav Namestnikov and Nikita Kucherov.
On November 16, 2013, Brown scored his first career NHL goal in a 6–3 loss to the Phoenix Coyotes.
On June 6, 2014, the Lightning announced the re-signing of forward Brown to a two-year, one-way contract. He appeared in 63 games with the Lightning during the 2014–15 season, posting four goals and 19 points while averaging 13:02 in ice time per game. Brown also played in all four Stanley Cup playoff games in 2014, notching two assists in Tampa Bay's four-game series defeat at the hands of the Montreal Canadiens in the Eastern Conference Quarter-finals. During the post-season, Brown was averaging 14:59 minutes in ice time.
On May 3, 2015, Brown scored his first career Stanley Cup playoff goal in a 6–2 Lightning win over the Montreal Canadiens in the Eastern Conference Semi-finals.
On June 24, 2016, the Lightning announced the re-signing of Brown to two-year contract extension. Brown played in 78 regular season games during the past season, recording eight goals and 22 points. Brown was tied for third on the team with a plus-16 rating. Brown set career bests in games played, goals, points, plus/minus and penalty minutes last season. He also appeared in nine Stanley Cup Playoff games, recording two assists and two penalty minutes. Brown has skated in 198 career NHL games, all with the Lightning over four seasons, registering 15 goals and 51 points. He also has skated in 37 playoff games, recording a goal and six points.
On October 15, 2016, Brown skated in his 200th career NHL game, which came during a 3–2 Lightning win over the visiting New Jersey Devils.
J. T. Brown (ice hockey)