Six of the matches are suspended until the end of the 2009-2010 season.
Barton has also been handed a £25,000 fine after he admitted a charge of violent conduct.
A release by the FA read: “At an independent Regulatory Commission hearing today, Newcastle United midfielder Joey Barton was given a 12 match suspension, six matches of which are suspended until the end of the 2009-2010 season, and fined £25,000.
“Barton admitted a charge of violent conduct relating to an assault on his then Manchester City team-mate Ousmane Dabo at City’s Carrington training ground on 1 May 2007.”
A statement from the independent Regulatory Commission Chairman Maurice Armstrong said: “Much has been written about Mr Barton over recent months. The Regulatory Commission had the benefit of taking all appropriate information into consideration. The Commission members considered principally the serious attack by Mr Barton that clearly cannot be accepted.
“The members also had to take into consideration the sanctions imposed by the courts and the pro-active support Mr Barton has received from Newcastle United FC and other professional bodies.
“The Commission members wanted to punish the offence appropriately but give Mr Barton an opportunity to ensure his professional conduct does not falter again and ensure he is fully aware of the consequences should he make another serious error of judgement.”
