One of 67 counties in Pennsylvania, United States. County seat: Kittanning. Named after John Armstrong Sr.

One of 23 counties in Maryland, United States. County seat: Prince Frederick.

One of 159 counties in Georgia, United States. County seat: Greenville.

A county of Nevada, United States. County seat: Tonopah.

One of 254 counties in Texas, United States. County seat: Corpus Christi.

A county of Nova Scotia, Canada. / One of 100 counties in North Carolina, United States. County seat: Halifax. / One of 95 counties in Virginia, United States. County seat: Halifax.

One of 105 counties in Kansas, United States. County seat: Hutchinson.

One of 8 counties in Connecticut, United States. There is no county seat, in common with all counties in Connecticut.

One of 100 counties in North Carolina, United States. County seat: Yadkinville.

One of 88 counties in Ohio, United States. County seat: St. Clairsville.