Barrister Jim Allister is to succeed DUP leader Ian Paisley as the party's European Parliament candidate.
The Six Counties elects three Members of the European Parliemant (MEPs) under a proportional representation system.
Paisley had topped every European election poll in the Six Counties since 1979 until he opted out this year.
Ulster Unionist MEP Jim Nicholson will be defending his seat again in June, while former northern health minister Bairbre de Brun will challenge for Sinn Féin.
Sinn Féin is also contesting the election in the South through Dublin candidate Mary Lou McDonald.
The SDLP will select a replacement for John Hume, who is also stepping down from Europe after 25 years, at a special convention in Cookstown on March 6.
The DUP's 90-member executive chose Allister over three Stormont Assembly members - party chairman Maurice Morrow, former Mid-Ulster and South Antrim MP the Rev William McCrea and Newry and Armagh Assembly member Paul Berry.
His selection marked as comeback to the party which he angrily retired from in 1987 when he was prevented from contesting an Ulster Unionist seat in East Antrim in the General Election.
Mr Allister said: "I am obviously delighted to be chosen as the DUP candidate.
"I am very honoured to be selected as the candidate for Europe for the main unionist party in Northern Ireland. I am delighted to fill the seat, which Dr Paisley held for so long and so well.
"I have a responsibility to deliver as he delivered."