The 6-foot-5 Hall, who played in 30 games with Oklahoma City's G League team, joins the Thunder for the second time this season.
He appeared in five games over November and December, scoring five points in 21 total minutes. In a preseason game against Memphis, he scored 19 points in 23 minutes.
After playing four seasons at Virginia, Hall was selected by the Thunder with the No. 53 overall pick in the 2018 NBA draft.