The former Democratic Unionist Party (DUP) MP Nigel Dodds is to become a life peer.
He had represented the North Belfast constituency in the House of Commons from 2001 until his defeat in the general election last year.
His elevation to the House of Lords had been widely expected.
He said: "I feel very honoured and humbled to be granted a peerage and a seat in the House of Lords."
The DUP's former Westminster leader lost his seat in the Commons to Sinn Féin's John Finucane in November last year.
Mr Dodds' political career spans 35 years, having first been elected to Belfast City Council in 1985.
"I have always endeavoured to represent all of my constituents to the very best of my ability in whatever forum I have had the honour to serve," he said.
"At this new juncture of my career I am pleased to have the opportunity to continue to serve the people of Northern Ireland in Parliament."
The DUP leader Arlene Foster said Mr Dodds was "widely recognised and respected... for his record of public service and his strong advocacy for the union and Northern Ireland's place within it".
This week it emerged Mr Dodds was one of several senior DUP figures who advised Mrs Foster against going ahead with a controversial bill in the Stormont assembly.
Eleven of the party's MLAs later rebelled by abstaining on the bill's final vote.
Mr Dodds' wife Diane is the economy minister in the Northern Ireland Executive.
The Northern Ireland-born former Labour MP Kate Hoey is also to become a lord.
She represented the Vauxhall constituency in London for 30 years but did not contest the last election.