Hall, a senior, was injured while covering a punt in the second quarter of the Cavaliers' 17-9 loss at Miami on Friday night. He was carted off the field after an air cast had been placed on the ankle.
He had surgery Sunday, and coach Bronco Mendenhall said the recovery timeline is uncertain.
Hall led the nation with 22 pass breakups in 2018 and tied for the lead with 24 passes defended. He was rated as the No. 20 prospect in 2020 NFL draft rankings by ESPN's Todd McShay.
Mendenhall said junior De'Vante Cross will start in Hall's absence. Cross came to Virginia as a quarterback and has also played wide receiver and safety for the Cavaliers.
The Associated Press contributed to this report.