The deal includes a player option for the third season, sources said.
McGee enjoyed arguably the best season of his career as the backup center and stopgap starter on a dominant Phoenix Suns team last season, averaging near career highs in points and rebounds on a per-minute basis. He proved to be a key depth piece for Phoenix after the Suns lost Frank Kaminsky for the season with a knee injury and saw Deandre Ayton miss several games.
McGee gives Dallas some much-needed rim protection and a big lob-threat target for Luka Doncic. McGee joins Christian Wood as the second frontcourt addition Dallas made this offseason after getting crushed on the boards by Golden State in the Western Conference finals.
McGee told ESPN he expects to be the Mavs' starting center. "I saw some opportunities out there where I was like, 'Oh yeah, if they had a rolling big, they could dominate in a different aspect,'" McGee said of choosing Dallas and playing with Doncic.
Entering his 15th season in the NBA, McGee has been a part of three championship teams -- two with the Golden State Warriors (2017, 2018) and one with the Los Angeles Lakers (2020). He is also reuniting with Mavs head coach Jason Kidd, who was on Frank Vogel's staff during L.A.'s run to the title.
A pure rim-rolling center, McGee has averaged 1.5 blocks while shooting 57.6% from the field for his career.