Sweeney, 48, replaces Peter Chiarelli, who was fired April 15. Sweeney, who has served the past six seasons as the assistant general manager, becomes the eighth GM in franchise history. The 2015-16 season will be his 10th in the Bruins' front office.
Sweeney was introduced in a news conference Wednesday afternoon, joined by Bruins CEO Charlie Jacobs and president Cam Neely. Jacobs described the moment as a "new era for Boston Bruins hockey," and started his statement by saying it was a "great day" for the organization.
"It's really a transition for us from where we were and where we want to go," Jacobs said. "Where we were last season was a team that didn't make the playoffs. Where we want to go is a team that's going to compete for the cup year-in and year-out and have a consistent winning team. And I find that Don is the best candidate for that."
Sweeney was selected among four final candidates, a process that Neely said took longer than he had expected. Given Sweeney's knowledge of the organization, in addition to his passion for the team, Neely felt that he was best for the job, noting that their personal friendship wasn't a factor in the decision.
"I certainly wouldn't hire a friend to be general manager of the Bruins -- it's a very important role in any organization," Neely said. "It's something that I know Don is going to do a great job at. That's first and foremost. We feel that Don will be extremely good at this job."
"I'm very, very excited and grateful for the opportunity," Sweeney said. "It means a lot to have gone through this process -- as exhaustive at times as it was, as challenging as it was -- and come out the other side knowing that they have the confidence in me to take this organization forward."
One of Sweeney's first orders of business will be addressing personnel, something he said will start with deciding the future of coach Claude Julien. Given the responsibility of handling every aspect of the team's hockey operations, Sweeney said there will be changes going forward. Whether that means Julien will be fired remains to be seen.
"I spoke to Claude again this morning, and I spoke to him as a person now in the general manager's seat," Sweeney said. "I have some things that I want to sit down with Claude and go through in a very orderly fashion as to where I think things need to change and what direction we need to change as a group.
"He's the coach of the Boston Bruins as of today, for sure."
Sweeney added that he is comfortable with the team's current front office and will look to find somebody to help take over the duties he previously held as assistant general manager.
Sweeney, a Harvard graduate, played 15 of his 16 seasons with the Bruins. He played more than 1,000 games for Boston, acknowledging his pedigree as a former player will aid him in his new role.
"I'm really happy for Don," Bruins center Patrice Bergeron said. "I have seen how hard he has worked to get this opportunity and I think that he has the experience to be really successful. I spoke with him briefly this morning and I am excited for him."
Sweeney said he hopes to place an emphasis on communication and will look to reach out to each and every player on the team in order to make sure everyone is on the same page.
"When we went through the process of interviewing candidates, that was a strong point of ours -- the communication process," Neely said. "For me, Don's the GM. He's going to be the GM. He's going to make the decisions and the communication is going to be there. It has to be there."
Sweeney inherits a roster that totaled 96 points in the regular season, narrowly missing the playoffs for the first time in the past eight seasons.
"I'm excited about the challenge in front of us to get back to where we need to get to," Sweeney said. "We're not as far away as what people may think."