- Ortonville, MN
- Oak Hill, OH
- Oak Harbor, OH
- Orange, CA
- Oswego, NY
- Osprey, FL
- Oneida, KY
- Olive Hill, KY
- Orting, WA
- Owasso, OK
- Osceola Mills, PA
- Oneida, NY
- Ohio City, OH
- Oakland, IL
- Oviedo, FL
- Ozark, MO
- Orleans, IN
- Orem, UT
- Orleans, VT
- Oconto, WI
- Oxford, GA
- Orléans, ON
- Orange, MA
- Ogden, UT
- Oregon, IL
- Ozark, IL
- Oneonta, NY
- Oshkosh, WI
- Oliver, WI
- Okemah, OK
- Odem, TX
- Ono, PA
- Okanagan Falls, BC
- Oak Grove, AL
- Osceola, IN
- Olmsted Falls, OH
- Oakdale, NY
- Oil Springs, KY
- Ozone Park, NY
- Orillia, ON
- Ozark, AR
- Oakville, ON
- Oglesby, IL
- Orland, CA
- Oliver, BC
- Oakland, OR
- Okanogan, WA
- Oxford Mills, ON
- Oak Ridge, NJ
- Oak Creek, WI
- Oskaloosa, IA
- Oakville, CT
- Okeechobee, FL
- Odessa, FL
- Odessa, TX
- Osyka, MS
- Orangeburg, SC
- Orange Cove, CA
- Oakbank, MB
- Oakland, NJ
- Otisville, MI
- Oto, IA
- Onamia, MN
- Opelika, AL
- Omaha, NE
- Oshawa, ON
- Oroville, CA
- Ontario, CA
- O'neill, NE
- Orosi, CA
- Oakland, CA
- Oxford, FL
- Oswego, KS
- Ozark, AL
- Okatie, SC
- Overgaard, AZ
- Omak, WA
- Ocilla, GA
- Osage, IA
- Oxford, ME
- Olar, SC
- Osborn, MO
- Oxnard, CA
- Orleans, MI
- Ottumwa, IA
- Olanta, SC
- Owego, NY
- Old Orchard Beach, ME
- Owensville, MO
- Okmulgee, OK
- Old Saybrook, CT
- Oakley, CA
- Oklahoma City, OK
- Oakland, ME
- Oakwood, OH
- Ontario, NY
- Oelwein, IA
- Oakfield, ME
- Ontario, OR
- Otisville, NY
- Orlovista, FL
- Owings, MD
- Orleans, MA
- Owen Sound, ON
- Olney, IL
- Osceola, WI
- Olmito, TX
- Oakland, MD
- Oak Hill, FL
- Oyen, AB
- Oaks, PA
- Oneill, NE
- Oconto Falls, WI
- Ogdensburg, NY
- Oscoda, MI
- Osoyoos, BC
- Olivehurst, CA
- Oakridge, OR
- Oberlin, OH
- Orrstown, PA
- Oceanside, CA
- Olive Branch, MS
- Old Town, FL
- Owensboro, KY
- Owosso, MI
- Orange, NJ
- Oneonta, AL
- Old Bridge, NJ
- Odenville, AL
- Orono, ME
- Old Forge, PA
- Oak Ridge, TN
- Owens Cross Roads, AL
- Orrington, ME
- Opelousas, LA
- Ottawa, IL
- Orange Park, FL
- Oxford, NJ
- Orange, TX
- Oxford, AL
- Oak Harbor, WA
- Oldtown, ID
- Oceanside, NY
- Osceola, AR
- Olathe, KS
- Ocala, FL
- Orlando, FL
- Oakwood, GA
- Olympia, WA
- Odenton, MD
- Orange City, FL
- Otonabee, ON
- Opa Locka, FL
- Ocean Springs, MS
- Olean, NY
- Oronoco, MN
- Outlook, WA
- Onawa, IA
- Owendale, MI
- Oskaoosa, IA
- Ottawa, OH
- Ottawa, ON
- Oak Hill, WV
- Oak Lawn, IL
- Oostburg, WI
- Orland Park, IL