JAMES Brokenshire has been appointed Northern Ireland Secretary, Downing Street said.
Old Bexley and Sidcup MP Mr Brokenshire, a married father of three, arrives at the NIO after six years at the Home Office, where he held a number of posts, including Immigration Minister.
Mr Brokenshire supported Mrs May's bid to become Tory leader while Ms Villiers backed Andrea Leadsom.
DUP leader Mrs Foster congratulated the new incumbent at Stormont House.
"Looking forward to working with you," she tweeted.
The Irish Republic's minister for foreign affairs Charlie Flanagan said: "I warmly congratulate James Brokenshire on his appointment as Secretary of State for Northern Ireland and hope to have the opportunity of an early meeting with him.
"The post of Secretary of State for Northern Ireland carries significant responsibilities on important matters that remain within the competence of Westminster, such as security, parades and dealing with the legacy of the past. I wish Mr Brokenshire the very best as he assumes this important responsibility."
Delighted and honoured to have been asked by the Prime Minister to serve as Northern Ireland Secretary in her new Government.
— James Brokenshire (@JBrokenshire) July 14, 2016
Departing Northern Ireland Secretary Theresa Villiers said she leaves the post with the belief that the north is more stable than it has been for years.
Announcing her departure from front bench politics, the Chipping Barnet MP said new British Prime Minister Theresa May offered her a role in the British government, but it was not one she felt she could accept.
The former transport minister, who spent four years in the Northern Ireland Office, said she was confident further political progress would be made at Stormont to solidify the peace.
"I regret to say that I have left the government," she said.
"The new prime minister was kind enough to offer me a role but it was not one which I felt I could take on.
"I am very grateful to have been given the opportunity to serve on the front bench for 11 years, first in the shadow cabinet, then as transport minister, and finally as secretary of state for Northern Ireland for four years in David Cameron's cabinet."