The Senegalese forward was shown a straight red card after a high challenge on Manchester City goalkeeper Ederson.
A statement from the Football Association on Tuesday said: “Sadio Mane’s three-match suspension, which was effective immediately, remains in place after his claim of excessive punishment was rejected following an Independent Regulatory Commission hearing.”
Liverpool will now be without the winger for their clash against Burnley and two games against Leicester.
The controversial decision has split opinion all over the country, with pundits and managers being unable to agree on the verdict.
Liverpool boss Jurgen Klopp claimed neither he nor his City counterpart Pep Guardiola believed the foul deserved a red card.
Match of the Day pundits Alan Shearer, Gary Lineker and Ian Wright all said they would have gone for the ball in that scenario.
While Chris Sutton told Match of the Day 2 the incoming ban should be rescinded.
City's Ederson was seeing leaving the Etihad with a bandage over his face.
The player needed stitches to close the wound left by Mane's boot.
However the Brazilian has trained with him team-mates ahead of City's Champions League clash with Feyenoord.
Mane's challenge wasn't the only debatable issue of the weekend.
Newcastle United's Matt Ritchie and West Ham's Winston Reid both avoided being sent for an early bath despite both going for a high ball with their feet.
Liverpool take on Sevilla in the Champions League tomorrow evening.
It is unclear whether Mane will feature in the clash.
