Benjamin Harrison Eaton (December 15, 1833 – October 29, 1904) was an American politician, entrepreneur and agriculturalist in the late 19th and early 20th century.

Eaton was a founding officer of the Greeley Colony and was instrumental in the establishment of modern irrigation farming to Northern Colorado.

His projects were influential in helping turn the South Platte River valley into an important agricultural region in the state's economy.

He was an early prominent citizen of Fort Collins, the nearest post office and trading point, and was a charter member of the Masonic Lodge there.

In 1870 Eaton met Nathan Meeker, whom newspaperman Horace Greeley had dispatched to Colorado to pick the Union Colony site.

Eaton suggested the land southeast of his place, at the confluence of the South Platte and Poudre Rivers.

Eaton expanded his operations from farming into contracting, specializing in the building of irrigation canals and reservoirs, a business he heavily promoted as a means of bringing growth and wealth to Larimer and Weld Counties.

Competition for water between Fort Collins Agricultural Colony and the Greeley became desperate and in 1874 almost led to gunfire.

Ben Eaton and a few others calmed Greeley colonists with a commitment to divide the water according to need and a promise to deliver it.