Owned by New Balance, Warrior will produce Liverpool's home, away and third kits and the team's training wear in a deal that comes into force on June 1, 2012.
Warrior have traditionally been associated with ice hockey and lacrosse in the United States but general manager Richard Wright said: "We are here to shake up the world of football".
The deal has been reported as being worth £25million a year to Liverpool.
Ian Ayre, the club's managing director, said: "Liverpool FC is thrilled to be able to announce this fantastic partnership with Warrior Sports for the 2012-2013 Barclays Premier League season onwards.
"This is another landmark deal for Liverpool Football Club and once again shows the value of the club's brand globally.
"Warrior Sports will bring its own unique brand and ideas to the partnership, ensuring they can assist us at the club both on and off the field of play."
In a joint press release, the deal was described as "the starting point in Warrior Sports' global football journey".
Wright said: "At Warrior Sports we pride ourselves on high performance and an incredible desire to win.
"Our partnership with Liverpool FC, a football institution and recognised brand name across the world, is the perfect fit.
"Warrior Sports has ventured into football to bring our knowledge of making top level product to a new playing field.
"We are not the sort of brand that is going to keep our head down. We are here to shake up the world of football and our partnership with one of the most successful club teams of all time is just the start."