The deal, brokered by Vizeum, will feature Diet Coke idents before and after the show on Sky Living HD and product placement within the programme.
The brand was last seen on TV with Mother London's last instalment in its 'Love It Light' campaign, which featured three female puppets, shortly after the agency lost the account.
'Styled to Rock' will be hosted by Girls Aloud singer Nicola Roberts, British designer Henry Holland and stylist Lysa Cooper, who has previously worked on a number of Rihanna's outfits.
The show celebrates the talent within the British fashion scene and searches for new, undiscovered fashion designers.
It will run for 10 weeks and follow 12 designers hand-picked by Rihanna to create outfits for a range of high-profile music artists, who are yet to be announced.
Zoe Howorth, marketing director, Coca-Cola Great Britain, said the sponsorship was part of Diet Coke’s wider 'Love It Light' campaign, which showcases the "lighter side" to fashion and life to the brand’s target audience of younger women.
She said: "Diet Coke is passionate about fashion and we're thrilled to be bringing our consumers a new regular style fix, celebrating creativity and championing inspirational young designers."
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