Barton was formally charged with assault by police after answering bail in Manchester on Thursday.
The 24-year-old was arrested in May after it was alleged he attacked his then team-mate Ousmane Dabo, 30, during a training session at the club's complex in Carrington, south Manchester.
Barton's lawyer: "Our client, Joey Barton, was today charged under... the Offences against the Person Act in relation to a training ground incident which occurred on May 1 this year.
"Joey strenuously denies the charge and welcomes the opportunity to clear his name in the public forum.
"No further statements will be issued."
He is now out of action after fracturing a metatarsal bone in his left foot during a pre-season friendly last week.
A spokeswoman for Greater Manchester Police said Joseph Anthony Barton was charged on Thursday with Section 47 assault.
He will appear at Trafford Magistrates' Court next Thursday.
The offence is understood to carry a maximum sentence of up to five years in jail on conviction.