| | | Boyle County | KY | 21021 | | Danville, KY 19220 | | Central | nonmetro county (rural) | nonspecialized | https://maps.google.com/?q=BoyleCounty+KY |
| | | Bracken County | KY | 21023 | | Cincinnati, OH-KY-IN 17140 | Cincinnati-Wilmington,
OH-KY-IN 178 | Outlying | metro county (urban) | manufacturing-dependent | https://maps.google.com/?q=BrackenCounty+KY |
| | | Breathitt County | KY | 21025 | | | | | nonmetro county (rural) | federal/state
government-dependent | https://maps.google.com/?q=BreathittCounty+KY |
| | | Breckinridge County | KY | 21027 | | | | | nonmetro county (rural) | farm-dependent | https://maps.google.com/?q=BreckinridgeCounty+KY |
| | | Bullitt County | KY | 21029 | | Louisville/Jefferson
County, KY-IN 31140 | Louisville/Jefferson
County--Elizabethtown,
KY-IN 350 | Central | metro county (urban) | nonspecialized | https://maps.google.com/?q=BullittCounty+KY |
| | | Butler County | KY | 21031 | | Bowling Green, KY 14540 | Bowling
Green-Glasgow-Franklin,
KY 150 | Outlying | metro county (urban) | manufacturing-dependent | https://maps.google.com/?q=ButlerCounty+KY |
| | | Caldwell County | KY | 21033 | | | | | nonmetro county (rural) | nonspecialized | https://maps.google.com/?q=CaldwellCounty+KY |
| | | Calloway County | KY | 21035 | | Murray, KY 34660 | | Central | nonmetro county (rural) | federal/state
government-dependent | https://maps.google.com/?q=CallowayCounty+KY |
| | | Campbell County | KY | 21037 | | Cincinnati, OH-KY-IN 17140 | Cincinnati-Wilmington,
OH-KY-IN 178 | Central | metro county (urban) | federal/state
government-dependent | https://maps.google.com/?q=CampbellCounty+KY |
| | | Carlisle County | KY | 21039 | | Paducah, KY-IL 37140 | Paducah-Mayfield, KY-IL 424 | Outlying | nonmetro county (rural) | farm-dependent | https://maps.google.com/?q=CarlisleCounty+KY |
