Barrios de Pennsylvania O
- Oak Lane-East Oak Lane (10)
- Oakwood (3)
- Old City (79)
- Old Uptown Harrisburg (11)
- Olde Kensington (68)
- Olney (20)
- Orchard Park (4)
- Outer Kenhorst/Shillington (2)
- Outer Lancaster (50)
- Outer Wilkes-Barre (8)
- Outer York/Valley View/Grantley (20)
- Outlet Area (1)
- Outlying South Allegheny (17)
- Overbrook (3)
- Overbrook (46)
- Oxford Circle-Castor (19)