Regions of United States
- Old Town Creek Watershed Dam Number 25
- Old Town Creek Watershed Dam Number 26
- Old Town Creek Watershed Dam Number 31
- Old Town Creek Watershed Dam Number 32
- Old Town Creek Watershed Dam Number 37
- Old Town Creek Watershed Lake Number 24
- Old Town Creek Watershed Lake Number 25
- Old Town Creek Watershed Lake Number 26
- Old Town Creek Watershed Lake Number Thirty-one
- Old Town Creek Watershed Lake Number Thirty-seven
- Old Town Creek Church
- Old Town Creek Watershed Lake Number Thirty-two
- Old Town Historic District
- Old Town Shopping Center
- Old Trinity Cemetery
- Old Union Baptist Church
- Old Union Branch
- Old Town Post Office (historical)
- Old Union Cemetery
- Old Union Cemetery
- Old Union Cemetery
- Old Union Cemetery
- Old Union Church
- Old Union Church
- Old Union Church
- Old Union Church
- Old Union Baptist Church
- Old Union Church
- Old Union Church
- Old Union Grove Church
- Old Union School
- Old Union School (historical)
- Old Vernon (historical)
- Old Vickers Cemetery
- Old Washington Church
- Old White Hall (historical)
- Old Wiggins Cemetery
- Old Zion Cemetery
- Old Zion Baptist Church
- Mount Zion Primitive Baptist Church
- Old Zion Church (historical)
- Old Zion Hill Cemetery
- Oldacre Hollow
- Old Union Cemetery
- Older Hill Cemetery
- Oldfield
- Oldfield Baptist Church
- Oldham Cemetery
- Oldham Chapel
- Oldham Creek
- Olde Acres
- Oleander Church
- Oleander Pond
- Olive Branch Baptist Church
- Olive Branch Cemetery
- Olive Branch Cemetery
- Olive Branch Church
- Olive Branch Church
- Olive Branch School (historical)
- Olive Branch School (historical)
- Olive Hill Cemetery
- Olive Hill School (historical)
- Olive J Dodge Elementary School
- Oliver
- Oliver Cemetery
- Oliver Church of Christ
- Oliver Church (historical)
- Oliver Creek
- Oleander
- Oliver Dam
- Oliver Elementary School (historical)
- Oliver Heights
- Oliver Junior High School
- Oliver Lock and Dam
- Oliver School (historical)
- Oliver-Bedingfield Memorial Cemetery
- Olivers Chapel Church of Christ
- Olivers Chapel
- Olivers Ferry (historical)
- Olivers Lake
- Olivet Church (historical)
- Olivet Missionary Baptist Church
- Olland
- Ollie
- Olmsted (historical)
- Olney
- Olson Pond
- Olustee
- Olustee Creek
- Oliver Creek
- Olympia Spa Country Club
- Omaha
- Omar (historical)
- Omar Post Office (historical)
- Omega
- Omega (historical)
- Omega Assembly of God Church
- Omega Baptist Church
- Omega Cemetery
- Omni
- Omusee Creek
- Olusty Creek (historical)
- Omussee Creek Sewage Treatment Plant
- Onemile Bayou
- Omusee Creek Public Use Area
- Oneonta Church of Christ
- Oneonta City Hall
- Oneonta Elementary School
- Oneonta High School
- Oneonta Industrial Park
- Oneonta Methodist Church
- Oneonta Post Office
- Oneonta Recreation Park
- Ono Island
- Point Ono
- Onycha
- Opelika
- Opelika High School
- Opelika Junior High School
- Opelika Post Office
- Opelika Public School (historical)
- Opelika State Technical College
- Open Acres
- Open Acres Baptist Church
- Open Door Baptist Church
- Open Door Christian Fellowship Church
- Open Door Baptist Church
- Open Door Church
- Open Door Church
- North River Christian Academy
- Open Pond
- Open Pond
- Open Pond Lookout Tower
- Open Pond Recreation Area
- Open Pond Recreation Area
- Ophelia S Hill Elementary School
- Ophir
- Opine
- Opine
- Opine Community House
- Opine Lake
- Opine Timber Company Dam
- Opintlocco Creek
- Oneonta
- Opossum Branch
- Opossum Branch
- Opossum Branch
- Opossum Creek
- Opossum Creek
- Opossum Hollow
- Opossum Hollow
- Opossum Hollow
- Opossum Valley
- Opossum Valley
- Opp
- Opp Country Club
- Opp Fishing Club Dam
- Opp Fishing Club Lake
- Opp High School
- Opp Middle School
- Opp Post Office
- Opp Public Library
- Optimist Lake
- Optimist Lake Dam
- Optimist Park
- Orange
- Orange Baptist Church
- Orange Beach
- Orange Beach Marina
- Orange Beach Presbyterian Church
- Orange Branch
- Opp City Hall
- Orange Cemetery
- Orange Hill
- Orange Hill Baptist Church
- Orange Hill School
- Orchard
- Orchard Baptist Church
- Orchard Creek
- Orange Cemetery
- Oregonia Cemetery
- Oregonia Baptist Church
- Oregonia School (historical)
- Original Church
- Original Church of God Sanctified
- Orion
- Orion Bridge
- Orion Cemetery
- Orion Church
- Orion Church
- Orion Institute (historical)
- Orlean Bullard Beeson Hall
- Orman Cemetery
- Orme Cemetery
- Orneys Place Pond
- Oro Point
- Orono (historical)
- Orono Mine
- Orphans Creek
- Orchard Elementary School