Prime Time presenter David McCullagh is to become a co-presenter on the RTÉ Six One News.
Mr McCullagh will join Caitríona Perry on the flagship news programme.
He will begin co-presenting the show in September.
Mr McCullagh said: “After seven very enjoyable years on Prime Time, I'm really looking forward to joining Caitríona on the Six One News and continuing the work of our much loved colleague Keelin Shanley.”
Keelin Shanley, a former Six One anchor with Ms Perry, died at the age of 51 earlier this year.
“Over the last few months the need for accurate information has never been greater, and viewers have turned to RTÉ News and Current Affairs in astonishing numbers,” added Mr McCullagh.
“We aim to continue meeting that need, bringing viewers all the news of the day, as well as the big interviews that get to the heart of the issues.”
Director of RTÉ News & Current Affairs Jon Williams described McCullagh as one of Ireland’s “most formidable journalists”.
“A former RTÉ Political Correspondent, and acclaimed historian, there could be no-one better equipped to join Caitríona on Six One as Ireland emerges from this emergency facing some difficult challenges, and heads towards the centenary of the foundation of the State.”
Mr McCullagh graduated with a PhD in Politics from UCD.
He joined RTÉ in 1993 as a reporter having worked at the Evening Press before that.
He spent 12 years as RTÉ News Political Correspondent and he has hosted Primer Time since 2013.
He has also written four books.
“David brings vast experience as a presenter and as a correspondent to the Six One News,” said Ms Perry.
“I’m very excited about our new partnership and look forward to working with him and the team to take the programme into the next phase.”