A few teams expressed interest in St. Louis.
He chose to sign with the Tampa Bay Lightning as he believed they were the most likely to give him playing time in the NHL.
He made his debut with the team on October 6, 2000.
He struggled at first, failing to score a goal in the first six weeks of the season and again found himself out of the lineup at times.
Realizing that he was at a career crossroads, St. Louis abandoned the changes to his game that his NHL coaches had impressed on him, trusting his own instincts.
He scored his first goal of the season in late November, and finished the season with 18 goals and 40 points – 34 of which came after December 1.

While leading the team with 16 goals midway through the 2001–02 season, St. Louis suffered a broken leg following an awkward check by Josef Melichar of the Pittsburgh Penguins in a late January game.
Consequently, he appeared in only 53 of Tampa Bay's 82 games, finishing with 35 points.
He had a breakout season in 2002–03, finishing fourth in team scoring with 70 points and tying Vincent Lecavalier for the team lead with 33 goals.
He led the team in plus-minus at +10 and appeared in his first NHL All-Star Game.
St. Louis won the puck control relay event and finished second in the fastest skater events of the 2003 All-Star Game's skills competition.
He scored his first career hat-trick on January 30, 2003, in a game against the Carolina Hurricanes.
In the playoffs, Tampa Bay won its first playoff series in franchise history when they eliminated the Washington Capitals.
Three of St. Louis' seven goals were game-winners, including the overtime goal in the sixth game that won the series.
He led the team with 12 points in 11 playoff games.

St. Louis exceeded his previous season in 2003–04, capturing the Art Ross Trophy as the NHL's leading scorer with 94 points.
He finished fourth overall with 38 goals and his plus-minus of +38 led the league.
He scored his 100th career goal on February 17, 2004, against the Philadelphia Flyers.
He led the 2004 playoffs with 15 assists and finished with 24 playoff points in 23 games.
He led the Lightning to the Stanley Cup Final against Calgary, against whom he scored the overtime winning goal in game six to force a deciding seventh game of the series.
The Lightning won the game 2–1 to secure the franchise's first Stanley Cup.
St. Louis won several post-season awards: He was named a First Team All-Star and voted recipient of the Lester B. Pearson Award as the NHL's most valuable player as selected by the players.
He also won the Hart Memorial Trophy as the NHL's most valuable player.
St. Louis was only the eighth player in NHL history to win the Art Ross and Hart Trophies and the Stanley Cup in the same season, and the first to do so since Wayne Gretzky in 1986–87.

While the 2004–05 NHL season was ultimately cancelled by a labour dispute, St. Louis spent it playing in Europe.
He signed a contract with HC Lausanne of Switzerland's National League A. He scored 25 points in 23 games.
When the NHL resumed in 2005–06, St. Louis signed a six-year contract extension with the Lightning worth US$31.5 million.
He finished with his third 30-goal season, but scored only 61 points on the campaign.
A few teams expressed interest in St. Louis. He chose to sign with the Tampa Bay Lightning as he believed they were the most likely to give him playing time in the NHL. He made his debut with the team on October 6, 2000. He struggled at first, failing to score a goal in the first six weeks of the season and again found himself out of the lineup at times. Realizing that he was at a career crossroads, St. Louis abandoned the changes to his game that his NHL coaches had impressed on him, trusting his own instincts. He scored his first goal of the season in late November, and finished the season with 18 goals and 40 points – 34 of which came after December 1.
While leading the team with 16 goals midway through the 2001–02 season, St. Louis suffered a broken leg following an awkward check by Josef Melichar of the Pittsburgh Penguins in a late January game. Consequently, he appeared in only 53 of Tampa Bay's 82 games, finishing with 35 points. He had a breakout season in 2002–03, finishing fourth in team scoring with 70 points and tying Vincent Lecavalier for the team lead with 33 goals. He led the team in plus-minus at +10 and appeared in his first NHL All-Star Game. St. Louis won the puck control relay event and finished second in the fastest skater events of the 2003 All-Star Game's skills competition. He scored his first career hat-trick on January 30, 2003, in a game against the Carolina Hurricanes. In the playoffs, Tampa Bay won its first playoff series in franchise history when they eliminated the Washington Capitals. Three of St. Louis' seven goals were game-winners, including the overtime goal in the sixth game that won the series. He led the team with 12 points in 11 playoff games.
St. Louis exceeded his previous season in 2003–04, capturing the Art Ross Trophy as the NHL's leading scorer with 94 points. He finished fourth overall with 38 goals and his plus-minus of +38 led the league. He scored his 100th career goal on February 17, 2004, against the Philadelphia Flyers. He led the 2004 playoffs with 15 assists and finished with 24 playoff points in 23 games. He led the Lightning to the Stanley Cup Final against Calgary, against whom he scored the overtime winning goal in game six to force a deciding seventh game of the series. The Lightning won the game 2–1 to secure the franchise's first Stanley Cup. St. Louis won several post-season awards: He was named a First Team All-Star and voted recipient of the Lester B. Pearson Award as the NHL's most valuable player as selected by the players. He also won the Hart Memorial Trophy as the NHL's most valuable player. St. Louis was only the eighth player in NHL history to win the Art Ross and Hart Trophies and the Stanley Cup in the same season, and the first to do so since Wayne Gretzky in 1986–87.
While the 2004–05 NHL season was ultimately cancelled by a labour dispute, St. Louis spent it playing in Europe. He signed a contract with HC Lausanne of Switzerland's National League A. He scored 25 points in 23 games. When the NHL resumed in 2005–06, St. Louis signed a six-year contract extension with the Lightning worth US$31.5 million. He finished with his third 30-goal season, but scored only 61 points on the campaign.
Martin St. Louis