"It's an unbelievable feeling. I can't wait to get started with them," he told TSN. "I can't wait to meet all the guys and play for an unbelievable organization. We have a very young team, very talented players.
"I think I can learn a lot from everybody. I hope I can make the team as fast as possible."
The left wing, who turns 19 on Jan. 15, was the No. 3 pick in the 2020 NHL Draft. Stuetzle said he hopes to join the Senators for training camp after playing for Germany at the 2021 IIHF World Junior Championship in Edmonton. Ottawa opens the 2020-21 season on Jan. 15 against the Toronto Maple Leafs at Canadian Tire Centre.
"Tim possesses an exceptional blend of both speed and skill and a playmaking ability that our fans are going to enjoy watching for several years to come," Senators general manager Pierre Dorion said. "He's a dynamic forward who we expect to become a key piece of our roster as we continue trending towards icing an eventual elite-level team."
Stuetzle scored 34 points (seven goals, 27 assists) in 41 games for Mannheim last season, his first playing in Germany's top professional league.