St. Louis was selected a finalist for the eighth time in 10 years on Tuesday. He won the award last season and in both 2010 and 2011 while playing for the Tampa Bay Lightning.
"It's an honor to be [nominated] for any award," St. Louis told ESPNNewYork.com's Katie Strang following the Rangers' morning skate in Philadelphia. "But I think my focus is on something bigger and better right now."
The Rangers are tied 1-1 with the Flyers in their best-of-seven first-round series that resumes Tuesday night.
The Lady Byng Trophy honors a person in the league who plays at a high level with good sportsmanship. The NHL will announce the winner of all of its awards on June 24 in Las Vegas.
Information from The Associated Press was used in this report.