Bloomfield will watch Friday’s FA Cup third round tie at MK Dons, with interim manager Craig Short remaining in the dugout, before taking the reins next week before the visit of Bristol City on 17 January.
A decision on Bloomfield’s coaching staff will be made in due course an Oxford statement said, while the club have not disclosed the length of his deal.
“I want my teams to work hard, attack with purpose and play with a clear identity,” Bloomfield added.
“Everyone has to understand their role, be accountable and deliver consistently.”
