Swydd Jefferson

Ceir sawl Swydd Jefferson yn yr Unol Daleithiau:

 Jefferson County, Alabama
 Jefferson County, Arkansas
 Jefferson County, Colorado
 Jefferson County, Efrog Newydd
 Jefferson County, Florida
 Jefferson County, Georgia
 Jefferson County, Gorllewin Virginia
 Jefferson County, Idaho
 Jefferson County, Illinois
 Jefferson County, Indiana
 Jefferson County, Iowa
 Jefferson County, Kansas
 Jefferson County, Kentucky
 Jefferson Parish County, Louisiana
 Jefferson County, Missouri
 Jefferson County, Mississippi
 Jefferson County, Montana
 Jefferson County, Nebraska
 Jefferson County, Ohio
 Jefferson County, Oklahoma
 Jefferson County, Oregon
 Jefferson County, Pennsylvania
 Jefferson County, Tennessee
 Jefferson County, Texas
 Jefferson County, Washington
 Jefferson County, Wisconsin

ru:Джефферсон#Округа