The 27-year-old right-back had just over 12 months left on his previous deal which he signed on arriving from Aston Villa for a reported initial £1m in June 2015.
He has appeared in 28 of Burnley's 30 league matches this season.
"I had a year left, but when the club and the manager approached me about a new deal it was a no-brainer," he said.
Burnley defender Matt Lowton has extended his contract at Turf Moor to the end of the 2019-20 season.