Okinawa

OKA

Oklahoma City

OKC

Olbia

OLB

Omaha

OMA

Oporto

OPO

Oran

ORN

Orlando

MCO

Osaka

OSA

Oslo

OSL

Ostend

OST

Ostersund

OSD

Ottawa

YOW

Ouagadougou

OUA

Oudja

OUD