The 31-year-old, who joined the Clarets from Wolverhampton Wanderers in August 2014, has penned a fresh deal until the summer of 2019, while the contract includes the option to extend the agreement for a further 12 months.
"It's great and long may it continue. I'm delighted to have signed. It's just great to be part of a club like this at the minute and hopefully we can have another successful season," Ward told Burnley's official website.
Ward, who has played in two European Championships for his country, appeared in 37 of Burnley's 38 Premier League matches during the 2016-17 season.