General manager John Hammond announced the signing Wednesday. Terms of the deal were not disclosed.
The 6-foot-9 O'Bryant averaged 8.2 rebounds and 5.4 rebounds in five NBA Summer League games in Las Vegas, playing about 18 minutes a contest. O'Bryant averaged 12.7 points and 7.7 rebounds in three seasons at LSU before being selected with the 36th overall pick last month.
Milwaukee signed forward Jabari Parker - the second overall pick — this month. This was a key draft for a franchise with new ownership and new coach Jason Kidd coming off an NBA-worst 15-67 record.