Kate Middleton wears ‘The Roger Advantage’ tennis shoes in white/juniper from On Running.
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On is a Swiss athletic shoe and performance sportswear company.
The tennis shoes are from a collaboration between On and Swiss tennis star Roger Federer.

To date, the Princess has only worn the shoes once in public. Knowing that Kate is the patron of the Lawn Tennis Association and she attends sports-related related engagements regularly, I suspect we’ll see her wear these shoes again in the future.