The five-figure deal will see Appleton's branding across all signage, programmes and the trophy itself.
Previous sponsors of the event include Land Rover, Ebel, BMW, Rotary Watches and Pommery Champagne.
James Robinson, Appleton Estate Rum brand manager, said polo was the perfect sport for Appleton to be associated with because the brand is drunk by "a discerning and distinguished clientele".
Appleton will have its own polo team competing, consisting of high-profile players Jack Kidd, Jamie Morrison, Andrea Vianini and James Harper.
Robinson said: "Developing links with the world of polo will underline the brand's own credentials as one of the world's finest rums."
Appleton will also have a themed bar at the event, which will take place at Berkshire Polo Club on May 27.
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