American tennis star Ben Shelton is reportedly parting ways with Swiss sportswear brand On to sign an endorsement deal with New Balance. According to reports from Hard Court, the 24-year-old Grand Slam finalist will officially join the Boston-based athletic label in January, marking the first high-profile athlete departure from On since French footballer Kylian Mbappé acquired a minority equity stake in the company.

Shelton, who reached the 2026 US Open final and recently finished runner-up at the Paris Masters to Carlos Alcaraz, previously anchored On’s performance tennis line alongside world No. 1 Iga Świątek and Flavio Cobolli. While On maintains its presence in tennis backed by investor Roger Federer, Shelton’s move transitions him to New Balance’s expanding roster. There, he aligns with longtime friend Coco Gauff, baseball superstar Shohei Ohtani, and Olympic track champions Sydney McLaughlin-Levrone and Femke Bol.

The reported switch highlights ongoing athlete movement across tennis apparel, following recent defections such as Frances Tiafoe joining Lululemon, Taylor Fritz signing with Hugo Boss, and Jack Draper partnering with Vuori. With his contract set to commence at the start of the new calendar year, Shelton becomes the latest marquee talent to bolster New Balance’s elite global sports ambassador portfolio.