He made an early impact by earning the first piece of league hardware for the franchise's modern incarnation, and guided the club to its lone Stanley Cup Finals appearance in 2007. Along the way, he provided Ottawa hockey fans with a plethora of memories that not even a final season with the Detroit Red Wings could erase.
As the Senators get set to honor their all-time leader in games played (1,178), goals (426), assists (682) and total points (1,108) prior to Thursday's game against the New York Islanders, here's a look at five moments that defined Alfredsson's legacy in Ottawa.
The expansion Senators - who joined the league for the 1992-93 regular season - were intentionally built through the draft, with top picks like Alexei Yashin, Alexandre Daigle, Radek Bonk and Bryan Berard expected to serve as the building blocks for success.
It was a sixth-round pick, however, that made the biggest and longest-lasting impact in Ottawa. Drafted 133rd overall by the Senators in 1994, Alfredsson made his NHL debut a year later, recording 26 goals and 35 assists to lead the team in scoring in 1995-96 en route to winning the Calder Memorial Trophy as the NHL's top rookie.
He was named captain of the team prior to the start of the 1999 season.
After the Toronto Maple Leafs moved to the Eastern Conference prior to the 1998-99 season, a natural geographical rivalry was born with the also Ontario-based Senators.
Tension between the Senators and Maple Leafs reached new heights when the two clubs met in the 2000 Stanley Cup Playoffs, the first of four postseason meetings in five years.
Alfredsson himself became public enemy No. 1 in Toronto during Game 5 of a second-round series in 2002, when - late in the third period - he infamously hit forward Darcy Tucker from behind and subsequently scored the game-winning goal seconds later.
The Leafs beat the Senators in all four playoff meetings in the early 2000s, but this moment continues to draw ire in the streets of Toronto.
As a result, the Senators advanced to the Stanley Cup Final for the first time in modern history. While they were defeated in five games by the Anaheim Ducks, the Prince of Wales Trophy marks the most significant team achievement during Alfredsson's tenure in Ottawa.
Alfredsson scored 14 goals and added eight assists in 20 games during that run to the finals.
On Jan. 24, 2008, Alfredsson further cemented his legacy with the Senators by setting the team record for most points in a single game.
Alfredsson scored a hat-trick and added four assists in a game against the Tampa Bay Lightning, Ottawa's expansion cousins. The outburst placed him at the top of the NHL scoring list at the All-Star break.
He finished the season with 40 goals and 49 assists in 70 games, marking the best point-per-game single-season average of his career.
With all eyes on Ottawa as the city hosted its first All-Star Game in 2012, Alfredsson scored two goals in 91 seconds and added an assist, coming oh so close to a hat-trick and MVP honors.
Still, Alfredsson was the brightest of stars over the course of the weekend, widely celebrated by the Senators' faithful. The game was rightfully embraced as an opportunity to express appreciation for all he had done for the city and the hockey community at large.