For months, Anthony had expressed a desire to leave the Denver Nuggets after eight seasons, with his native New York considered his preferred landing place.
Several media outlets, including ESPN and New York's Daily News, said the deal was completed late Monday with the Knicks acquiring Anthony and giving him a three-year contract extension worth $65 million. New York also gets Renaldo Balkman, Chauncey Billups, Anthony Carter and Sheldon Williams.
The Nuggets receive Wilson Chandler, Danilo Gallinari, Raymond Felton and Timofey Mozgov in addition to $3 million in cash, and a first-round and two second-round picks in the 2014 draft.
New York was also involved in a trade with the Minnesota Timberwolves in which Eddy Curry and Anthony Randolph were sent to Minnesota in exchange for Corey Brewer.
"This was a long process and Carmelo is relieved that it is over and he's thrilled to be joining the Knicks," Leon Rose, Anthony's agent, said in a statement. "He and I appreciate how the Denver Nuggets and the fans have treated him over the years and Carmelo wishes nothing but the best for the franchise, the fans and the city."
The Nuggets chose Anthony, 26, as the third overall selection in the 2003 NBA draft. He's played 564 games for Denver, averaging 24.8 points a game. This season, Anthony is averaging 25.2 points a game.