"I've got one goal and that's to win a Cup, and I feel my best chance is here," Ruff said. "There wasn't a question of leaving at all because we've worked hard at this. We've put a lot of work to getting it to where it's at. ... It would be foolish to step away from it now."
Ruff signed a new three-year contract with a fourth-year option, and Regier agreed to a two-year deal.
Both of their contracts had expired and their return allows the Sabres to keep together the architects of a team that reached the Eastern Conference the past two years.
Ruff and Regier have worked together in Buffalo since 1997, and currently represent the longest serving coach-general manager partnership in the NHL.
"I'm very excited to continue the work," Regier said. "I think where we left off this past season and what we have to look forward to is both exciting and incomplete. So it's an opportunity to continue down that road."
Their season ended when the top-seeded Sabres were eliminated by Ottawa in Game 5 of the conference finals last month.
Sabres managing partner Larry Quinn said the deals were agreed to before the start of the playoffs.
Without providing figures, Quinn added both agreed to financial terms that he believed "were substantially below what they would receive anywhere else in the National Hockey League. But it shows their level of commitment here."
Now the Sabres will try to keep co-captains Chris Drury and Daniel Briere, both eligible for free agency on July 1.