Cornelius Cornwell (? - ?) was an early Ypsilanti industrialist, constructing Ypsi's first paper mill in 1856, a mill which employed up to 500 people, as well as 5 other paper mills in the area. Cornwell's son(?) Clark Cornwell served as Ypsilanti Mayor's from 1886-1888.

The Gothic Revival / Queen Anne Cornwell Residence, built in 1883 at 203 N. Huron, was the first home in Ypsilanti to have a telephone - installed as a direct line to the paper mill. Reports vary as to whether it was the largest home between Detroit and Chicago at the time of its construction, or merely the largest example of the style.

In addition to the paper mill business, Cornwell constructed the Occidental Sanitorium in Ypsi, claiming that water found when constructing the first paper mill had healing powers. The sanitorium was driven out of business by the 1907 Pure Food & Drug Act; bottles from the water are on display at the Ypsilanti Historical Museum.

Cornwell is buried in Highland Cemetery at B1 70, Lot 10, in a grave marked with a large granite sphere.