The mum-of-one, who is pregnant with her second child, will be heard as the voice trumpets, which pop out of the ground.
Speaking about her new role, Fearne said: "Teletubbies holds a special place in my heart so I'm honoured to be part of this well-loved TV show.
"As a mum, I am sure the new series will enthral a whole new generation of children across Britain and I will certainly be watching with my kids."
Joining Fearne on the revamped show, which is due to air on CBeebies later this year, is actress Jane Horrocks, who is best known for playing Bubbles in ‘Absolutely Fabulous’.
The actress will voice the ‘tubby phone’ - a mobile-style gadget aimed at bringing the revamped show into the modern day.
"I am very excited to be playing the tubby phone in the new series," Jane said.
"The series has a whole new feel to it. I think it's hilarious and it will appeal to adults as much as it does children."
Tinky-Winky, Dipsy, Laa-Laa and Po are set to return to our screens later this year
Last month it was rumoured that Oscar-winning actor Jim Broadbent would also be providing one of the voices on the show, which has now been confirmed by the BBC.
Speaking about his latest role, he said: "Teletubbies is truly a British institution and it's very exciting to be involved in bringing this global hit back to our TV screens."
Jane Horrocks and Jim Broadbent
The revamped series will feature the same characters and style as the original show, which ran from 1997 to 2001, but with a "refreshed and contemporary look".
The original ‘Teletubbies’ series was watched by around one billion children in more than 120 countries in 45 languages.
But one person who won’t be tuning into the new series will be its creator Anne Wood.
"I couldn't bring myself to [watch the new series],” she told the BBC earlier this year.
"I have nothing against them, it might be brilliant. They tell me they've got the best producer possible on it, so that's a good sign.
"But how could I watch it? All my programmes are like my children. It's like seeing a child remade in somebody else's image. So good luck to them."