A two-time Stanley Cup winner (2012, 2014), Martinez scored the Cup-clinching goal in double overtime of Game 5 against the New York Rangers in 2014. He'll try to help the Golden Knights make the Stanley Cup Playoffs for the third time in as many seasons since joining the NHL. Vegas is tied with the Edmonton Oilers for first place in the Pacific Division.
"Good player. He's going to make us better. He's been well-coached. He's won," coach Peter DeBoer said. "Talked to him a little bit about system stuff. [Kings coach] Todd [McLellan] does a lot of things similar to what we do as language and verbage and things like that, so I don't think it'll take him long to get him up to speed. Happy to have him. Excited to have another veteran presence back there."
Golden Knights defenseman Brayden McNabb, who played with Martinez in Los Angeles, said, "He's a great player, ton of experience, Stanley Cups. Plays the right way, moves hard, very reliable defensively. It's a great pickup for us."
Los Angeles (21-34-5) is last in the Western Conference and will not make the Stanley Cup Playoffs for a second straight season.
"Quality individual. First-class guy. Very mature, bright, smart, an incredible work ethic. Championship qualities," Kings coach Todd McLellan said of Martinez. "A guy where you can see why they've won here in the past, when you have those type of players are contributing on a daily basis. They had the pieces they needed to win. Everybody talks about [Anze] Kopitar, Doughty, [Marian] Gaborik and some of those guys from those championship teams, but Toffoli and Martinez played a huge role in it, and I can see it now."
The Kings on Monday traded forward Tyler Toffoli to the Vancouver Canucks for forward Tim Schaller, forward prospect Tyler Madden, a second-round pick in the 2020 NHL Draft and a conditional pick in the 2022 NHL Draft. The NHL Trade Deadline is Feb. 24.
"We were having dinner together and he was sitting right next to me," Martinez said of Toffoli being told. "Obviously, we know the situation at hand. But anytime you have one of your best friends traded, that's disappointing. At the same time, he's got a good opportunity in Vancouver. They have a good team and they gave up a lot to get him. It's always good to go somewhere you're really wanted, in that regard. Disappointment, but I'm happy that he's going somewhere where someone wants him and he's in a good situation."
Selected by Los Angeles in the fourth round (No. 95) of the 2007 NHL Draft, Martinez has 198 points (62 goals, 136 assists) in 597 regular-season games and 16 points (six goals, 10 assists) in 64 Stanley Cup Playoff games.
"He's a very good shot-blocker," Kings defenseman Drew Doughty said. "Good skater, gets his shots through from the point. A good little [wrist shot] on him. He can hammer one-timers, too, actually. Good defensively. The game's kind of going a different direction [with] offensive D-men, so [Alec's] a good two-way defenseman that's going to make any team better. He's a professional as well, and a good person."
NHL.com staff writer Tim Campbell and NHL.com Independent Correspondent Danny Webster contributed to this report