The deal announced Thursday will keep the 35-year-old under contract through the 2014-15 season.
St. Louis had 29 goals and 94 points last season and received the Lady Byng Award as the league's most well-behaved player. He was the NHL's leading scorer in 2004, when he helped Tampa Bay win its only Stanley Cup title.
New Lightning general manager Steve Yzerman announced the extension, which kicks in after next season, when St. Louis is due to earn about $4 million.
"Today is a great day for the Lightning organization," Yzerman said. "Marty means so much to this franchise, both on and off the ice. His hard work and dedication are unsurpassed and we are thrilled that he will finish his career here in Tampa Bay."
St. Louis appeared in all 82 games last season. His streak of 390 consecutive games is the fourth longest among active players.
Tampa Bay also signed goalie Dan Ellis to a $3 million, two-year contract, a source told ESPN.com's Pierre LeBrun.
Ellis, who was an unrestricted free agent, will earn $1.5 million a year. His rights were traded to Montreal on Tuesday but he was unable to reach agreement with the Canadiens before free agency opened Thursday.
ESPN.com's Pierre LeBrun and The Associated Press contributed to this report.