Union Mill or Union Mills may refer to:
British Isles
Communities Union Mills, a village on the Isle of Man
Windmills Union Mill, Appledore, a windmill in Kent Union Mills, Burnham Overy, a combined wind and watermill in Norfolk Union Mill, Beverley, a windmill in the East Riding of Yorkshire Union Mill, Cranbrook, a windmill in Kent Union Mill, Gainsborough, a windmill in Lincolnshire Union Mill, Gilberdyke, a windmill in the East Riding of Yorkshire Union Mill, Hackney, a windmill in Middlesex Union Mill, Lynstead, a windmill in Kent Union Mill, Onehouse, a windmill in Suffolk Union Mill, Whitby, a windmill in the North Riding of Yorkshire Union Mills, Thurning a windmill in Norfolk Boreas Union Mill, Pontefract, a windmill in the West Riding of Yorkshire
Watermills Union Mills, Burnham Overy, a combined wind and watermill in Norfolk
Textile mills Union Mills, Milnsbridge, Yorkshire Union Mills, Skipton, North Yorkshire
United States (by state) Communities Union Mills, Indiana, an unincorporated community Union Mills, Iowa, an unincorporated community Union Mills, Maryland, an unincorporated community Union Mills, Virginia, an unincorporated community Union Mills, Pleasants County, West Virginia, an unincorporated community
Watermills Union Mills (Fall River, Massachusetts), listed on the National Register of Historic Places (NRHP) Union Mill Complex, Ballston Spa, NRHP-listed
Other Union Mills Homestead Historic District, Westminster, Maryland, NRHP-listed Union Mills Superintendent's House, Olympia, NRHP-listed in Thurston County