- New York Bay1
- Newberry County (S.C.)1
- Niagara (N.Y.)1
- Oconee County (S.C.)1
- Oconee County (SC)1
- Ohio Drainage1
- Ohio River, Louisville, Jefferson County, Kentucky, United States2
- Ohio River, Ohio, United States1
- Ohio River, United States3
- Ohio, United States17
- Okinawa (Japan)1
- Orangeburg County (S.C.)2
- Orangeburg County (S.C.), Laurens County (S.C.), Oconee County (S.C.)1
- Oregon, United States2
- Paris (France)1
- Pee Dee1
- Pendleton, Anderson County, South Carolina, United States1
- Philadelphia, Philadelphia County, Pennsylvania, United States2
- Pickens County2
- Pickens County (S.C)1