The award was made on the second anniversary of MacLean becoming Ottawa's head coach.
He guided the Senators into the Stanley Cup playoffs this season, where they pulled off a first-round surprise by ousting the No. 2 seed Montreal Canadiens. Pittsburgh knocked the Senators out in the Eastern Conference semifinals.
MacLean was a finalist for the Adams Award last year before losing out to Ken Hitchcock of the St. Louis Blues.
Other NHL honors handed out Friday included:
-- General Manager of the Year Award to Pittsburgh's Ray Shero.
-- Frank Selke Trophy (best defensive forward) to Jonathan Toews of the Chicago Blackhawks.
-- Bill Masterton Trophy (perseverance, sportsmanship) to Minnesota goaltender Josh Harding.
-- Lady Byng Memorial Trophy (sportsmanship, excellence on the ice) to Tampa Bay winger Martin St. Louis.
-- King Clancy Memorial Trophy (leadership) to Boston's Patrice Bergeron.
Other awards will be announced on Saturday prior to the second game of the Stanley Cup Finals, in which Chicago owns a 1-0 lead over Boston.
Among the awards on Saturday's schedule will be the Hart Memorial Trophy, which goes to the league's most vaulable player. Sidney Crosby, Alex Ovechkin and John Tavares are the nominees for the honor.