The 24-year-old helped Yorkshire to the??LV= Division One County??Championship title last year but may not feature until the final three games of the 2015 competition due to the Black Caps’ ODI tour of??Zimbabwe and South Africa.
“I’m delighted to be returning to Yorkshire for my third spell,” said Williamson.
“I have enjoyed my time over the last couple of years, and to be given the opportunity to return to the club is great.
“There is a brilliant culture at Yorkshire and it is a real privilege to be??part of it.”
Yorkshire have already secured the services of overseas stars??Aaron Finch and Glenn Maxwell of Australia and veteran??Pakistan batsman Younus Khan ahead of the 2015 campaign.