Union County

Ceir sawl lle o'r enw Union County gan gynnwys:	

 Union County, Arkansas
 Union County, Florida
 Union County, Georgia
 Union County, Illinois
 Union County, Indiana
 Union County, Iowa
 Union County, Kentucky
 Union County, Mississippi
 Union County, New Jersey, y dref mwyaf poblog o'r 17
 Union County, Mecsico Newydd
 Union County, Gogledd Carolina
 Union County, Ohio
 Union County, Oregon
 Union County, Pennsylvania
 Union County, De Carolina
 Union County, De Dakota
 Union County, Tennessee