Bergeron, 36, was named on 194 of 195 ballots submitted by the Professional Hockey Writers Association and placed first on 160 of those ballots. Calgary Flames forward Elias Lindholm placed second (21 first-place ballots), and Florida Panthers center Aleksander Barkov (10 first-place votes) was third.
The win moved Bergeron past Hall of Fame forward Bob Gainey of the Montreal Canadiens, with whom he was tied with four Selke wins. Bergeron previously won the award in 2012, 2014, 2015 and 2017.
This was also the 11th consecutive season Bergeron was named a finalist for the award, which set another NHL record. He had been tied with Wayne Gretzky, who was a Hart Trophy finalist for 10 straight seasons.
Bergeron led the NHL in faceoff wins for the seventh time in his career, winning 61.9% of his draws. He had 25 goals and 40 assists in 73 games for the Bruins this season.
Bergeron, who does not have a contract for next season, has played all 18 of his NHL seasons in Boston. He said Sunday that he is recovering from surgery to repair an elbow tendon. Bergeron said the surgery took place Tuesday and that the recovery time is usually 10 to 12 weeks.
He said he is still unsure whether he'll return for a 19th season. He turns 37 in July.
"I still think I have a lot of time in front of me, I guess, to make that decision,'' Bergeron said. "I want to make sure that I take all the time that I need to make the right one.''
Not having a contract for next season is the primary rationale behind Bergeron's indecision.
"My whole career I've had contract extensions or I've had long-term contracts," he said. "I would head into the summers I guess with that in the back of my mind, meaning that I know what I'm doing next year and all that stuff. And now I'm 36 and I don't have a contract and I can actually take a step back for the first time in my career, the first time in my life that I can just reflect on what I do want looking forward for the future.''
The Associated Press contributed to this report.