The sponsorship deal is the first between the two parties.
DHL will take responsibility for the distribution of United's range of merchandise, including match programmes and shirts, across the world.
In return, DHL will be offered a range of consumer marketing and B2B marketing activities across a number of United platforms.
These include digital advertising on perimeter boards, matchday programmes, branding on the club website, and at events hosted at Old Trafford.
DHL will also work with the Manchester United Foundation, the club's community initiative, to develop a series of programmes to help improve the lives of vulnerable people in local communities.
The ccommercial deal has been overseen by David Gil, Manchester United chief executive, and Phil Couchman, chief executive of DHL (UK & Ireland).
United's shirt sponsor is US finance giant Aon. Other commercial partners include Turkish Airlines, Audi and Thomas Cook.