Murray will also be featured in the brand's wider marketing campaigns and wear its sports apparel, footwear and accessories from January onwards.
He joins the likes of ski racer Lindsey Vonn, American footballer Cam Newton and fellow tennis player Sloane Stephens on Under Armour’s roll of athletic partnerships.
Ryan Kuehl, Under Armour’s senior category director, global golf and tennis, said: "Signing Andy is really a special moment for the brand, as we continue to elevate and diversify our athlete roster and expand our international presence. Andy’s remarkable character, competitive spirit and unmatched ability make him the perfect fit for our family."
Matt Gentry, Murray’s manager, added: "Andy is very committed and focused when it comes to training and preparation, so the new partnership with Under Armour is an exciting and ideal match. Athlete performance and product innovation are the brand’s core pillars, which will have strong benefits for Andy and the team in 2015 and beyond."
Read more: In pictures: Judy Murray serves coffee for Lavazza at Wimbledon
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