Also signing Wednesday were defenceman Sean Curry, an unrestricted free agent, and goaltender Jordan Sigalet, a restricted free agent.
Hamill has spent the past four seasons with the Everett Silvertips of the Western Hockey League, scoring a franchise-record 187 points (61 goals, 126 assists) in 183 career games. He won the Bob Clarke Trophy as the WHL's top scorer last season with 32 goals and 61 assists.
The 18-year-old is scheduled to play for Canada in the Under-20 Summit Series against Russia in September.
Curry has spent the past two seasons with the Providence Bruins of the American Hockey League, scoring nine goals with 12 assists and amassing 266 penalty minutes in 136 games. He spent his first three professional seasons in the Carolina Hurricanes organization.
Sigalet spent the past two seasons in Providence with a goals-against average of 2.47 and a record of 34-16-4.