Mercer County

Ceir sawl sir o'r enw Mercer County yn yr Unol Daleithiau, gan gynnwys:	

 Mercer County, New Jersey
 Mercer County, Illinois
 Mercer County, Kentucky 
 Mercer County, Missouri 
 Mercer County, Gogledd Dakota
 Mercer County, Ohio 
 Mercer County, Pennsylvania 
 Mercer County, Gorllewin Virginia