Flags of the counties of England.
English County Flags
Flags of the Counties of Ireland redesign [OC]
A map of Irish counties, with the county flag.
Flag of Yorkshire
Cook County Flag regular--full color patch (sheriff police fire) IL Illinois
County flag of Surrey, UK
Maryland counties flag map [OC] [1134x673] (x-post from /r/vexillology)
Flag of Alpine County, California
Map of UK Counties in Great Britain, Northern Ireland, and in addition Ireland (which is not in the UK).