Steen took first star honours, leading all players with 11 goals in the opening month of the season. He scored in nine of 10 games with a 35.5 shooting percentage as the Blues took 16 of a possible 20 points in October.
He posted five multi-point games, including a four-point performance against the New York Rangers on Oct. 12. The Winnipeg-born Swede is also tied for second in the league with four power-play goals.
Crosby was named the second star for October, scoring eight goals and adding 13 assists for a league-high 21 points.
His excellent start helped the Penguins to first place in the Metropolitan Division.
The native of Cole Harbour, N.S., has six multi-point games this season, including his eighth career regular-season hat trick Oct. 12 versus the Tampa Bay Lightning.
Finnish goaltender Niemi was named third star, posting a 9-1-2 record with a 1.72 goals-against average, .924 save percentage and two shutouts in helping the Sharks earn a league-best 22 points in October.
Niemi finished the month with a share of the NHL lead in wins and shutouts, while also placing in the top three in goals-against average and minutes.