Gervinho was sent off for slapping Joey Barton in the face after the Magpies midfielder had dragged him to his feet when he went down in the area.
Barton felt the Ivory Coast international was trying to gain an unfair advantage and earn his side an undeserved penalty, which triggered his reaction.
Arsenal lodged an appeal on Monday, citing that the standard three-game ban was "clearly excessive".
FA regulatory commission: "Arsenal's Gervinho has had his three-match suspension for violent conduct confirmed today.
"The player was sent off during Arsenal's fixture against Newcastle United at St James' Park on Saturday.
"Arsenal subsequently lodged a claim that the standard punishment of three matches was clearly excessive.
"A commission heard the claim today and dismissed it, meaning the player must serve a three-match suspension with immediate effect."
The suspension means Gervinho will miss Arsenal's next three Premier League games against Liverpool, champions Manchester United and promoted Swansea City.