St. Louis was honored in a pregame ceremony Friday night before the Lightning's 3-1 loss to the Columbus Blue Jackets.
A key member of Tampa Bay's 2004 Stanley Cup championship team, St. Louis holds the franchise record for points (953) and assists (588).
"Wow. What a night," said St. Louis, who teared up during his speech when talking about his late mother. "It's such an incredible honor."
Those speaking at the ceremony included Blue Jackets coach John Tortorella, who coached the 2003-04 Lightning, NHL commissioner Gary Bettman and Tampa Bay captain Steven Stamkos.
"Every day wanting to be better and making his teammates better -- it's such an inspiration to me to have been part of his journey," Tortorella said. "I just have so much respect for how he did it. It's just unbelievable."
St. Louis began his NHL career with the Calgary Flames (1998-2000) and signed with Tampa Bay as a free agent in 2000, playing there until 2014, when he was traded to the New York Rangers. He retired from playing in July 2015.
"He was, still is, and forever will be the heart and soul of this organization," Stamkos said.
Blue Jackets player Nick Foligno, who scored a go-ahead power-goal in the game, said it was special moment for him.
"It was just amazing to see and be able to celebrate a player that we all admired that we grew up watching or played against,'' Foligno said. "I thought, for one, it was an amazing thing to experience and a pretty proud moment for him and his family.''