Mrs Foster has joined the network as a contributor, in her first role since stepping down as Northern Ireland First Minister.
GB News, positioned as a rival to the current affairs offerings of the likes of the BBC and Sky, is fronted by veteran broadcaster Andrew Neil.
Mrs Foster was unveiled as a contributor on the Political Correction show, presented by former Ukip leader Nigel Farage.
Mrs Foster said she joined the station to bring Northern Ireland into the mainstream of UK politics.
“It’s very exciting to be here with such an august number of people this morning,” she added.
Asked why she joined the show, she said: “Two reasons really – first of all I see it as an opportunity to have a space for a civilised discussion in a meaningful way.
Watch: Arlene Foster steps down as first minister
“Very often political programmes are very short and snappy and there’s not enough opportunity to develop stories.
“The second reason is to bring Northern Ireland into the mainstream of UK politics. It’s something I feel very passionate about, something that I have thought of as a student, a very long time ago.
“That is the opportunity in GB News and I am really looking forward to it.”
Mrs Foster took part in discussions on topics including Brexit, vaccine passports, the Northern Ireland Protocol and social media abuse.
GB News has captured a host of high-profile signings, including former Sky Sports presenter Kirsty Gallacher, ex-BBC presenter Simon McCoy and former ITV presenter Alastair Stewart.
It broadcasts seven days a week across the UK and Ireland.
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