The veteran midfielder returns to Turf Moor, just six months after signing for Glasgow giants Rangers.
However, the 34-year-old's ill-fated stay at Ibrox just five Scottish Premiership games before being released.
Barton was released by Rangers in November
Barton was released by Rangers in November
Barton's last match north of the border came in September and he now heads back to Lancashire in a bid to help the Clarets retain their Premiership status.
The decision to re-sign Barton had been complicated by a Football Association probe into alleged betting, with the player facing a possible fine and suspension after being charged for allegedly placing 1,260 bets over a 10-year period.
A statement from the Premier League club reads: "Burnley Football Club can confirm that following detailed discussions regarding the recent FA charge brought against Joey Barton, the club have reached an agreement with the player and his representatives over a contract with the club until the end of the season.
"Barton becomes available for selection from January 3 after that completing his registration in time to serve a one match suspension against Manchester City, as a result of a carry-over suspension passed down from Scottish FA related to a previous offence."
Burnley's next match on Saturday FA Cup third round tie at Sunderland.