The Australia international midfielder has signed a three-year contract.
Coach Kevin Muscat said he was delighted to be adding a player of Valeri's quality to his squad.
"Carl has a wealth of football experience and will be a very valuable addition to our club and we can't wait to see him in Victory colours," Muscat said.
"He's played at the highest level in Italy, one of the best leagues in the world, as well as impressing on the biggest stage at the 2010 World Cup in South Africa.
"Carl is a versatile midfielder and I have no doubt he will have an impact on the A-League and we are very much looking forward to his leadership around the club also."
Valeri said he was over the moon to be returning to Australia to be part of Melbourne's 2014/15 Championship tilt.
"I've certainly watched and admired the A-League from afar," Valeri said.
"The league just keeps getting better and better each season and I'm really looking forward to being back home and playing in a competition that has such great potential.
"You just to have to look at all the quality young players over in Brazil with the Socceroos to see how far the game has come in this country. A lot of those boys started their professional careers in the A-League, and that speaks volumes.
"The opportunity to join Melbourne Victory and work with Kevin (Muscat) was one I certainly couldn't pass up and I can't wait for training to get underway."
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