Mair earned a slight raise above the $675,000 he made last season. The deal was announced by his agent, Robert Gerow, and reached a day before Mair was eligible to become an unrestricted free agent.
The seven-year NHL veteran spent the past four seasons with Buffalo. He had two goals and nine assists in 82 games last season and added a career-high five points (1-4) in 16 playoff games.
"Adam is an important part of this team and we are glad to have him under contract for three more years," said Sabres GM Darcy Regier. "He brings veteran leadership and a passionate physical presence to the Buffalo Sabres."