The 23-year-old forward, who was a restricted free agent, scored an NHL career-high 34 points (17 goals, 17 assists) in 56 games last season. He was tied for second on the Senators in goals behind forward Connor Brown (21) and his five power-play goals were tied for second behind forward Josh Norris (six).
"Drake represents an integral component of our future at forward," general manager Pierre Dorion said. "Dating to his first pro season, he has steadily progressed to the point where he is now widely recognized as a bona fide top line NHL winger. He possesses a strong ability to play at both ends of the ice, is a key power-play contributor and someone we expect to be a prominent player for us for several years to come."
Batherson was selected by Ottawa in the fourth round (No. 121) of the 2017 NHL Draft. He has scored 53 points (23 goals, 30 assists) in 99 NHL games.