The former Newcastle and Manchester City midfielder rejected a one-year contract at Burnley to team up with Mark Warburton at the newly-promoted Glasgow club for two seasons.
Rangers have confirmed the signing of Joey Barton on a two-year deal.
Barton joins the Glasgow club, which will play in the Scottish Premiership next season after winning promotion under Mark Warburton, having rejected a one-year deal at Burnley.
The 33-year-old was named Burnley's Player of the Year as the Clarets made an immediate return to the Premier League in 2015-16 - and was also voted on to the PFA Championship Team of the Year - but has quit Turf Moor in search of a longer deal elsewhere.