The duo, who host The Polly and Grant Show on The Hits, told stunned listeners the news on their show this morning.
"For the last two weeks Polly and I have been living apart. We are separated."
Gillespie: "It isn't because we don't love each other, we are best friends, we love working together, we have wonderful children together. It's just life."
They say The Polly and Grant Show
Gillespie and Kereama spent more than 20 years at the helm of their ZM breakfast show before moving to The Hits last April.
The pair had been together for 30 years and have three children.