Hall, 28, was the most coveted unrestricted free-agent forward available this offseason, and he spent the weekend listening to pitches from at least a half-dozen teams.
Choosing the Sabres is a surprising move, considering that Hall has said that his No. 1 priority is the chance to win a Stanley Cup. The Sabres have not made the playoffs since 2011, the longest drought in the NHL.
"I certainly hope that the players and coaches and our staff and the organization are excited and our fans are excited,'' general manager Kevyn Adams said. "This is a great step. But we're in a position right now where we have to go earn it. We have to go get better every day.''
When asked in August what was most important as he shaped his free-agent decision, Hall told reporters: "I think, honestly, it's probably all winning."
Hall has played in only 14 postseason games in his 10-year NHL career. In Buffalo, he is expected to play on the wing alongside Jack Eichel.
"Awesome signing!" Eichel wrote in a text to ESPN's John Buccigross after news broke that Hall is headed to Buffalo.
The deal came together after the Sabres made landing Hall their top priority in free agency, with second-year coach Ralph Krueger playing an integral role.
Krueger was an assistant in Edmonton during Hall's rookie season, and he spent the 2012-13 lockout-shortened year as the Oilers' coach. In Hall's one season playing under Krueger, he had 16 goals and 34 assists for 50 points in 45 games.
"I think the way that Ralph had built a relationship with Taylor previously absolutely played a big role in this,'' Adams said. "I know they spent quite a bit of time over the last few days talking. That, to me, is what's critical in this: that we got to a place on both sides that there was a comfort level, and we all wanted the same thing.''
Hall was open to all proposals from teams on short- or long-term deals, a source told ESPN. However, the one-year commitment represents the biggest trend in this year's free-agency period. Many players are taking short-term deals, which is a reflection of uncertainty surrounding the coronavirus pandemic and the salary cap remaining flat at $81.5 million.
Adams explained that the short-term contract doesn't preclude the two sides from agreeing to a lengthier deal next offseason.
"We believe in Taylor as a player and a person, and we hope this turns into a long-term relationship for both sides that works,'' he said. "We'll see where that goes.''
Hall won the 2018 Hart Trophy as league MVP while with the New Jersey Devils. The Devils failed to make the postseason the following season, and they traded Hall to the Arizona Coyotes in December, as the Devils weren't in playoff position and realized they were not likely to sign Hall to a long-term contract.
The No. 1 pick of the 2010 draft spent the first six years of his career in Edmonton before he was traded to New Jersey for defenseman Adam Larsson in 2016. In 10 NHL seasons, Hall has scored 218 goals and 563 points in 627 career games. He put up a career-high 39 goals in his 2017-18 MVP season.
The Associated Press contributed to this report.