Signed as a free-agent in December, Williams played just eight games for the Mavs with most of his time being spent with the club's D-League affiliate, the Texas Legends, in nearby Frisco.
The move shaves the Mavs' roster to 14 and would allow the team to add a player. Among players recently bought out, J.J. Hickson has been picked up by Portland and Boris Diaw could be headed to San Antonio to join countryman Tony Parker. Others notables waived include Andres Nocioni, Mehmet Okur and 3-point specialist Jason Kapono.
Players waived by Friday and signed by another team are playoff eligible.
In his limited appearances with the Mavs, Williams averaged 3.6 points and 1.6 rebounds in 8.1 minutes. He was a quality asset for the Legends, playing in 24 games and averaging 14.7 points, 8.5 rebounds and 2.54 blocks.
Recent injuries to Mavs centers Brendan Haywood and Brandan Wright forced Williams to be recalled and then assigned to the Legends for the maximum three times allowed for a player on an NBA contract under rules of the new collective bargaining agreement.
Depending on interest in Williams from other NBA teams, he could sign with the Legends. He played 49 games for the team last season.