The Premier League has allowed clubs to wear sleeve sponsors since the start of last season, but United had remained one of the few not to take the plunge until now.
The deal will see the Kohler logo feature on the left sleeve of both United's men's and women's teams for the coming few seasons, while the partnership will also include 'joint participation on game day activities, innovative improvements to club facilities, global sustainability and social responsibility projects and other partner collaborations'.
Headquartered in Kohler, Wisconsin, a town named for the company itself, Kohler in 1873 and is known as a 'leader in the design and innovation of kitchen and bath products and one of the largest manufacturers of power systems in the world'.
United's brand new 2018/19 home kit, images of which were leaked online earlier this month, is due to be launched next week and the Kohler branding will feature for the first time in the club's opening pre-season tour game against Mexican side Club America in Phoenix on 19th July.
"It is a pleasure to welcome Kohler to the Manchester United family as a principal partner and our first shirt sleeve sponsor for both the men's and women's teams," United Group Managing Director Richard Arnold told the club's official website.
"Our shirt is much more than what we wear, it embodies the passion of our fans and their allegiance to the club," he added.
"Kohler is known around the world not only for its cutting-edge design and luxury products but also a genuine commitment to stewardship and sustainability and is an exciting addition to our family of commercial partners."