Financial terms of the deal were not disclosed.
"Tomas has been a consistent, productive player throughout his NHL career," Avalanche general manager Chris MacFarland said. "He is a veteran winger who brings scoring depth to our middle six and can contribute at both ends of the ice. We are excited to have him under contract for this season."
Tatar, 32, played in all 82 games last season with the New Jersey Devils, racking up 20 goals and 28 assists for 48 points. It was the sixth time in his career that he scored at least 20 goals in a season.
The Ilava, Slovakia, native also became only the second player in franchise history behind Patrik Elias (2000-01) to record 20 or more goals and have a +40 rating or better. He led the Devils and was fifth in the league with a +41 plus/minus rating.
A second-round pick (60th overall) by the Detroit Red Wings in the 2009 NHL entry draft, Tatar has 455 points (211 goals, 244 assists) in 783 career NHL games with the Red Wings (2010-18), Vegas Golden Knights (2018), Montreal Canadiens (2018-2021) and Devils (2021-2023).