Bonino, a 33-year-old forward, scored 26 points (10 goals, 16 assists) in 55 regular-season games with the Minnesota Wild last season, and did not score a point in seven Stanley Cup Playoff games.
"Nick is a proven, veteran center who has been a winner at every level of hockey he has played," Sharks general manager Doug Wilson said. "His skillset is well-rounded, bringing a lot of intangibles to our club, and he has a knack for playing his best when it means the most."
Selected by the Sharks in the sixth round (No. 173) of the 2007 NHL Draft, Bonino has scored 308 points (132 goals, 176 assists) in 681 regular-season games with the Wild, Nashville Predators, Pittsburgh Penguins, Vancouver Canucks and Anaheim Ducks, and 48 points (19 goals, 29 assists) in 105 playoff games.
Bonino won the Stanley Cup with the Penguins in 2016 and 2017.
Reimer, a 33-year-old goalie, was 15-5-2 with a 2.66 goals-against average and .906 save percentage in 22 games (21 starts) for the Carolina Hurricanes last season.
The Sharks acquired goalie Adin Hill and a seventh-round pick in the 2022 NHL Draft from the Arizona Coyotes on Saturday for goalie Josef Korenar and a second-round pick 2022.
"We've addressed our goaltending situation," Wilson said. "But I wanted to make sure we upped the competition level. So even though all those young players we've added, we've got guys that are quality vets coming in that understand come September, these young guys are going to have to come in and compete for spots. They'll be given opportunities but the quality of people, the leadership, the veteran presence, I feel very good about that."
Selected by the Toronto Maple Leafs in the fourth round (No. 99) of the 2006 NHL Draft, Reimer is 173-131-43 with a 2.79 GAA, .913 save percentage and 24 shutouts in 385 games (351 starts) with the Hurricanes, Florida Panthers, Sharks and Maple Leafs. He is 5-5 with a 2.70 GAA and .925 save percentage in 11 playoff games (10 starts).
"James is an experienced NHL goaltender who we know well from his previous stint in San Jose (eight games during the 2015-16 season)," Wilson said. "Along with Adin Hill, his addition helps solidify the goaltending position for our club and we're very excited to bring him back to the Sharks."
The Sharks also signed forward Andrew Cogliano to a one-year contract. The 34-year-old forward scored 11 points (five goals, six assists) in 54 games for the Dallas Stars last season.
Cogliano and Bonino were teammates with the Ducks for three seasons from 2011-14.
"Really pleased with the additions, the quality of people that we added," Wilson said. "I know the relationship between [Cogliano] and [Bonino] in particular is really a good thing. They talked a lot about what we were trying to accomplish here. These two guys are ultimate pros. You spend any time around them, to the preparation that goes in, how they practice, how they carry themselves, but the center position is so important."
Selected by the Edmonton Oilers in the first round (No. 25) of the 2005 NHL Draft, Cogliano has scored 410 points (170 goals, 240 assists) in 1,066 regular-season games with the Stars, Ducks and Oilers and 29 points (10 goals, 19 assists) in 100 playoff games.
"Andrew is a durable, versatile player who brings an element of speed and excels as a penalty killer," Wilson said. "His addition gives our coaching staff flexibility with an additional, trusted veteran presence on our forward lines."
NHL.com staff writer Tim Campbell contributed to this report