As exclusively revealed by Goal, the German sports manufacturer emerged as frontrunner to replace former sponsors Nike in April and has now clinched a world-record deal.
A statement read: "Manchester United plc (NYSE:MANU) has reached a 10-year agreement with adidas for a global technical sponsorship and dual branded licensing deal for a minimum guarantee of £750m, subject to certain adjustments, beginning with the 2015-2016 campaign.
"For the 2014-2015 season, Nike will continue in its role of technical sponsor and trademark licensee."
It represents a world record for any sportswear deal in any sport and dwarfs the fee paid by the same company to sponsor Chelsea's kit by £45m per season.
United's new Nike kit, their last under the current arrangement, was revealed earlier in July.