Barrios de Pennsylvania O
- Oak Lane-East Oak Lane (15)
- Oakwood (3)
- Old City (53)
- Old Orchard (1)
- Old Uptown Harrisburg (6)
- Olde Kensington (60)
- Olney (26)
- Orchard Park (4)
- Outer Kenhorst/Shillington (3)
- Outer Lancaster (64)
- Outer West York/Shiloh (19)
- Outer Wilkes-Barre (16)
- Outer York/Valley View/Grantley (24)
- Outlet Area (1)
- Outlying South Allegheny (18)
- Overbrook (6)
- Overbrook (67)
- Oxford Circle-Castor (31)