Robidas, 37, split last season with the Dallas Stars and Anaheim Ducks, scoring five goals and 10 points in 38 games. He was traded to the Ducks at the NHL Trade Deadline after spending parts of 11 seasons in Dallas.
"He's a heart-and-soul kind of a player," Toronto general manager Dave Nonis said. "He's a player I think that at the end of every year you can look back and say he's given you everything he had. He's still a very effective player."
Multiple media reports said Robidas' contract is worth $9 million, an average annual value of $3 million.
Robidas fractured his right leg during Game 3 of the Ducks' Western Conference First Round series against the Dallas Stars. He sustained a similar injury while playing for Dallas in a game against the Chicago Blackhawks on Nov. 29.
"We're very comfortable that injury isn't a factor, and will not be a factor going into this season," Nonis said.
Robidas was chosen by the Montreal Canadiens in the seventh round (No. 164) of the 1995 NHL Draft. In 885 NHL games with the Canadiens, Stars, Blackhawks and Ducks, he has 56 goals, 251 points, 679 penalty minutes and a plus-8 rating.
"His leadership, the way he plays the game, the fact he can be a second-power-play-unit guy at this stage of his career, the compete, the character, all those things we were looking to add, we were pretty happy that we were the team he ended up with," Nonis said.
The Maple Leafs also signed forward Leo Komarov to a four-year contract reportedly with an average annual NHL salary-cap charge of $2.95 million.
"Happy to be back in the capital of hockey," Komarov said on Twitter. "See you soon."
Komarov, 27, played his lone NHL season with the Maple Leafs in 2012-13, when he had four goals and nine points in 42 games.
Last season, he had 12 goals and 34 points in 52 games with Moscow Dynamo of the Kontinental Hockey League. He won a bronze medal with Finland at the 2014 Sochi Olympics, scoring no points with a plus-3 rating in six games.
"Leo offers a lot more than I think that we even got out of him two years ago," Maple Leafs general manager Dave Nonis said. "He's a better player, he's better offensively, he can play with good players, he's done that on the world stage with a pretty good hockey team.
"He's a guy that can play up and down the lineup and it was very important to us that we put a pretty good effort in to get Leo to come back here."