Ellicott's Mills was a flour milling company founded in the 18th century. Ellicott's Mills consisted of a group of buildings - a saw mill, a granite quarry, a grist mill, farms and a small village - in Oella, Maryland, on the east side of the Patapsco River from Ellicott City. The mills were founded by Joseph, John and Andrew Ellicott, Quarker brothers from Bucks County, Pennsylvania. Construction began in 1772, and the mills were operational by 1774. Tobacco had previously been a staple crop in the region (as with much of central and eastern Maryland), but the Ellicott brothers promoted a grain-growing revolution in the area. An additional flour mill was constructed in 1792, as well as a number of additional mills throughout the following two centuries. The Ellicotts sold their mill in 1844, but the site continued to be part of the flour industry for some time. Until 2020, Wilkins-Rogers, Inc. operated a flour milling plant located on the site of the original Ellicott flour mill.
Ellicott's Mills is today part of the Ellicott's Mills Historic District.