The trophy is awarded to the NHL player who shows "sportsmanship and gentlemanly conduct combined with a high standard of playing ability."
Marleau had his seventh 30-goal season in the past nine years, helping the Sharks reach the 100-point mark for the seventh time in that span while receiving just 18 penalty minutes. The 34-year-old Aneroid, Sask., native ranked second on the Sharks in goals (33) and was third in assists (37) and points (70).
Marleau native is a Lady Byng finalist for the second time, finishing third behind Pavel Datsyuk and Brad Richards in 2006.
O'Reilly put up a career-high 64 points as the resurgent Avalanche captured the Central Division title and tied a franchise record with 52 victories. He led the club in goals (28), power-play goals (nine) and game-winners (six, tie), and led the NHL in takeaways (83). The 23-year-old Clinton, Ont., native was flagged for just one minor penalty all season, joining Butch Goring (1977-78, Los Angeles) as the only players ever to receive two or fewer minutes over 80 or more games.
St. Louis won the Lady Byng last season, and is up for a repeat award after recording the seventh 30-goal season of his NHL career. The had 30 goals and 69 points with Tampa Bay and New York. The 38-year-old native of Laval, Que., was assessed just 10 penalty minutes.
The award is voted on by members of the Professional Hockey Writers' Association.