Caitríona Perry has announced that she is leaving RTÉ after almost 16 years.
The Six One News presenter will leave at the end of the month, according to the broadcaster.
She will be joining the BBC as News Chief Presenter and will be based in Washington DC.
Ms Perry previously worked in Washington DC as RTÉ News Washington correspondent from 2013 to 2017.
Announcing the news on social media, Ms Perry said it would be really hard to say goodbye and she was leaving with a mix of sadness and excitement.
"I am passionate about world news and US politics in particular, so it is really exciting to get the opportunity to be at the forefront of the BBC's coverage, bringing news to a global audience of nearly 500 million people," she said.
The Dubliner has previously written two best-selling and critically acclaimed books on US politics.
Ms Perry will use her summer break between jobs to pack up herself and her family and move to DC where she will "begin another chapter, picking up where we left off in 2018".
She took a moment to thank those who have tuned in to watch her over the years including those who have taken the time to write letters, cards and emails.
"Thank you also to all of those who have trusted me to tell their stories. As journalists, we rely on your bravery to stand up and speak out," she wrote.
She wish David McCullagh, her co-anchor on the Six One well for the future while he took to Twitter to express his sadness at her departure.
"What a fantastic job she's going to, and what a fantastic job she'll make of it," he said.
Ms Perry has been a co-presenter of the Six One News since January 2018, it is understood that a new co-anchor will be announced shortly.
Managing Director, RTÉ News and Current Affairs, Deirdre McCarthy said Ms Perry would be greatly missed.
"We are very proud to see such a talented Irish journalist go on to success on a global news stage," said Ms McCarthy.
"From working across all desks and platforms in the RTÉ newsroom, to her hugely impactful time as RTÉ News's Washington Correspondent to her calm and diligent presenting of the news to audiences each evening during national highs and lows, Caitríona's hard work and journalistic ethic always shone through."
When Ms Perry takes up the role at the BBC, she will join recently appointed chief presenter Sumi Somaskanda.
Paul Royall, Executive News Editor for the BBC News channel, said: “We are thrilled to welcome Caitríona to BBC News.
"She brings authority, expertise and warmth to the new channel, and completes a compelling on-air team.”
During her previous stint in the US, Ms Perry covered major news events such as the election and inauguration of Donald Trump, the Berkeley tragedy and also reported from North America, Cuba and Haiti.