Gudbranson made the Florida Panthers team for the 2011–12 season and made his NHL debut against the New York Islanders on October 8, 2011. He earned the first point of his NHL career on December 2, 2011, against the Los Angeles Kings, an assist. He scored his first NHL goal against Henrik Lundqvist of the New York Rangers during a 6–1 loss on December 11, 2011. At the end of the season, Gudbranson had two goals and eight points in 72 games, helping the Panthers reach the Stanley Cup playoffs for the first time since the 1999–2000 season. In the playoffs, Gudbranson was held pointless in seven games as Florida lost to the New Jersey Devils in the Eastern Conference Quarterfinals round.

In the 48-game, lock-out-shortened 2012–13 season, Gudbranson appeared in 32 games with Florida, earning four assists, as the club failed to reach the playoffs.

In the 2013–14 season, Gudbranson appeared in 65 games, scoring three goals and providing six assists. His defensive partner for the majority of the season was captain Ed Jovanovski, though he also spent time partnered with Dylan Olsen.

During the 2014–15 season, Gudbranson played in 76 games, scoring four goals and 13 points, both career highs. However, the Panthers failed to qualify for the playoffs for the third consecutive season.

Gudbranson played in 64 games in the 2015–16 season, scoring two goals and nine points, helping Florida into the playoffs for the first time since 2012. During the playoffs, Gudbranson was held off the score sheet in six games, as Florida lost to the New York Islanders in the first round (who won their first playoff series since 1993).

International

Year	Team	Event	Result		GP	G	A	Pts	PIM
2009	Canada Ontario	U17			6	2	2	4	0
2009	Canada	U18	4th		6	1	3	4	0
2010	Canada	U18	7th		6	0	1	1	4
2011	Canada	WJC			7	3	2	5	4
2014	Canada	WC	5th		8	1	0	1	6
Junior totals					25	6	8	14	8
Senior totals					8	1	0	1	6

Please see Photos (nice practice worn jersey) & Thanks for looking!