The defenseman, drafted first overall by the club at the 1996 NHL Draft, appeared in his 1,179th game on Thursday, eclipsing the mark set by long-time captain Daniel Alfredsson.
Phillips was honored by the team with a video tribute prior to the game against the Washington Capitals, while Alfredsson and former teammate Wade Redden joined general manager Bryan Murray in presenting him with a commemorative No. 1179 jersey.
Earlier in the day, Phillips said the key to his longevity is quietly going about his business.
"I just try and lead by example. Do what I do and let them see that if you quietly go about what's asked of you this is possible of anyone," he told Chris Stevenson of NHL.com. "I was a high draft pick, but never a superstar or anything like that, just a journeyman guy who put in hard work and time. Good, long stories can come of that."
Phillips, a prototypical stay-at-home defenseman, scored 71 goals and added 218 assists over the course of his first 1,178 games.
He also appeared in 114 playoff games for the Senators, helping the team reach the Stanley Cup Final for the first time in 2007 and recording his most memorable goal in a 2003 series with the New Jersey Devils.