Although terms of the agreement were not released, multiple media outlets reported last week that McGee would sign for a minimum contract.
The 29-year-old appeared in 77 games last season, averaging 6.1 points, 3.1 rebounds and just under a block a game. He shined in a first-round Western Conference playoff game against the Portland Trail Blazers, shooting 7-for-7 from the floor while scoring 15 points and blocking four shots in 13 minutes.
McGee's signing fills out the Warriors roster at the maximum of 15 players. Coming off its second championship in three seasons, the team re-signed Stephen Curry, Kevin Durant, Andre Iguodala, Shaun Livingston, Zaza Pachulia and David West earlier this summer while adding Omri Casspi and Nick Young in free agency.