Barrios de Illinois O

• O'Hare (12)
• Old Farm (3)
• Old Irving Park (17)
• Old Town (139)
• Old Town Chicago (1)
• Old Towne (2)
• Outer Loves Park/Machesney Park (11)
• Outer Northwest Rockford (21)
• Outer Rock Island/Moline (12)
• Outer South Rockford (20)