Barrios de Maryland O

• Oakenshawe (6)
• Oakland Mills (11)
• Oaklee (1)
• Old Town Hyattsville (26)
• Oldtown (1)
• Oliver (12)
• Otterbein (9)
• Outer Downtown/Maugansville (42)
• Outer Robinwood/Paramnt/Fountain Head (14)
• Outlying Annapolis (1)
• Overlea (7)
• Overlook (2)
• Owen Brown (7)