A Football Association Independent Regulatory Commission rejected a claim of wrongful dismissal after Sidwell saw red for a late challenge on Armand Traore after 79 minutes.
"Following an Independent Regulatory Commission hearing, Fulham's Steve Sidwell has had his claim for wrongful dismissal rejected," an FA statement read.
"Sidwell was dismissed for serious foul play during his side's game at home to Queens Park Rangers on 1 April 2013."
The 30-year-old's ban will begin immediately to rule him out of this weekend's trip to Newcastle, before matches against former clubs Aston Villa and Chelsea.
- Sports & Recreation
- Armand Traore