Phil Hogan has been named as the EU's new Trade Commissioner.
The European Commission's president-elect, Ursula von der Leyen, announced Mr Hogan's new role in a speech this morning.
She also announced other roles in the College of Commissioners.
Ms von der Leyen said her new team will "shape the European Way: we will take bold action against climate change, build our partnership with the United States, define our relations with a more self-assertive China and be a reliable neighbour, for example to Africa.
"This team will have to stand up for our values and world-class standards."
Announcing Mr Hogan, Ms von der Leyen said he "is known as a hard and a fair negotiator."
Nominees for commissioner roles must be interviewed by committees before confirmation.
Mr Hogan was made EU Agriculture Commissioner five years ago after being nominated for the post by former taoiseach Enda Kenny.
The 59-year-old was nominated as Ireland's commissioner for a second time by the Taoiseach Leo Varadkar in June.
Today I am grateful to present my well-balanced, agile and modern Commission that is led with determination, clearly focused on the issues at hand and provides answers. #EUstrivesformore pic.twitter.com/cF7SBxfhtp— Ursula von der Leyen (@vonderleyen) September 10, 2019
Mr Hogan said in a statement that he was "very pleased" to be nominated for the position.
"This is undoubtedly one of the most important economic portfolios in the College of Commissioners and the appointment comes at a very important time for the European Union," he said.
"International trade is the lifeline of the EU economy and its economic importance is illustrated by the fact that 1 in every 7 jobs in the EU is supported by the export of goods and services.
"Trade is a political priority for the European Commission and one with which I have been very closely involved during my term as Commissioner for Agriculture & Rural Development.
"As a result of our positive trade agenda, the EU has become the largest exporter of agrifood products in the world, with exports of €138 billion last year, supporting millions of jobs.
Mr Hogan added that he is "very much looking forward to starting in this exciting and challenging portfolio".
Mr Varadkar welcomed the appointment, calling it a positive development for Ireland.
"Ireland sought a major economic brief in the new European Commission, and I am very satisfied that we have secured it," said the Taoiseach.
"Commissioner Hogan will of course work for Europe as a whole, but it is a definite advantage to have an Irish person in charge of this crucial brief over the next five years.
"He will take the lead on the EU’s post-Brexit trade deal with the UK, as well as Mercosur and the EU’s trading relations with India, the US and China.
"Phil did an excellent job in the Agriculture and Rural Development brief. He is widely respected in Brussels and across the EU as a skilled negotiator and someone who builds alliances.
"We look forward to working closely with the new Commission President, Ursula von der Leyen, who has already shown a deep understanding of the negative impact Brexit could have on Ireland and across the EU."
As reported by the Irish Examiner last week, the role of trade going to an Irish commissioner is likely to trouble the British government and its Brexit negotiators - particularly if British ministers have to negotiate a new trade deal with the EU through Mr Hogan, who has been a vocal critic of Brexit and a staunch defender of the backstop.
Phil Hogan’s appointment as EU Trade Commissioner is a very positive development for Ireland. We sought a major economic brief in the new European Commission, and I am very satisfied that we have secured it.— Leo Varadkar (@LeoVaradkar) September 10, 2019
Pat McCormack - president of the Irish Creamery Milk Suppliers Association - welcomed Mr Hogan's appointment but warned that the new Trade Commissioner needs to protect the interests of rural Ireland.
“He is an Irish man, but he now has to wear a European hat. He needs to protect the primary producers out there,” Mr McCormack told RTÉ radio’s Today with Sean O’Rourke show.
“It is a welcome appointment and I put the challenge to him that he needs to protect Ireland’s interests in the event of any kind of Brexit.”
- additional reporting by Vivienne Clarke