The defender saw red in the Boxing Day win over Swansea after clashing with Alan Tate.
Referee Phillip Crossley also dismissed the Swans defender following the 19th minute altercation.
The R's appealed the decision and their claim was upheld by the Football Association's Regulatory Commission on Wednesday.
The suspension has been withdrawn and Hill, 32, is eligible to face Norwich on New Year's Day.
Source: PA
Source: PA