The 23-year-old, who was a restricted free agent, is one of nine defensemen expected to compete for a spot on Toronto's roster, along with Zach Bogosian, TJ Brodie, Justin Holl,
Mikko Lehtonen
,
Timothy Liljegren
, Jake Muzzin, Morgan Rielly and Rasmus Sandin.
"It's exciting. I mean, it's like a competition, so we'll see how camp goes," Dermott said. "Can't wait to get started. We're going to do that much better with that much more competition. It's going to get guys to push each other, and force guys to be their best version of themselves."
Dermott scored 11 points (four goals, seven assists) in 56 games with the Maple Leafs last season and had one assist in five postseason games.
"[Coach Sheldon Keefe] knows how I play when I'm at my best and I know how to play when I'm on my game," Dermott said. "I don't expect anything less than those guys biting at my heels to get in, and then try to steal my job. My job is to come in and play my game and do exactly what they want me to do. So it's just coming in and getting that done, and being consistent with it."
Selected by Toronto in the second round (No. 34) of the 2015 NHL Draft, Dermott has scored 41 points (nine goals, 32 assists) in 157 regular-season games and five points (two goals, three assists) in 19 Stanley Cup Playoff games.
NHL.com Staff Writer Mike Zeisberger contributed to this report