Wilshere was caught by television cameras raising his middle finger at City fans during the second half of Arsenal's 6-3 defeat at Eastlands on Saturday.
Although the incident was missed at the time by referee Martin Atkinson and his officials, the English Football Association was able to retrospectively implement disciplinary proceedings against the player under a new pilot scheme for 'not seen' incidents in Premier League matches.
As such, an independent three-man panel agreed if the gesture had been viewed during the game, then it would have merited a dismissal.
Arsenal submitted mitigating circumstances to the governing body, arguing the length of the punishment is excessive, but those submissions were rejected and so Wilshere will now miss both the crucial clash against title rivals Chelsea on 23 December as well as the Boxing Day trip to West Ham.
"The incident was not seen by match officials, but was caught on video.
"Whilst admitting the charge, Wilshere claimed the standard sanction for this offence was clearly excessive. The commission rejected this claim and the two match suspension will commence with immediate effect."