One of the key planets in Star Wars. It was home to the Dark Jedi, Freedon Nadd.

An citadel created by Onslaught with the aid of Franklin Richards in Central Park.

A province in Canada

Where Mumm-ra lives and schemes.

Now its own sovereign nation under President Veronica Cale, Oolong Island was home to the Science Squad and is currently home to the Doom Patrol.

The hidden city in the jungles of Africa.

The home of Starman.

Kingdom in Hyboria.

Namor's company in the 1990s.

A colonized planet that is culturally very similar to Europe during the Middle Ages. Members of the royal family of Orando have the innate ability to create realistic illusions with their minds. The most famous native of the planet is Princess Projectra, of the Royal House of Orando and a member of the Legion of Super-Heroes.

County located in California

The home of the Jetsons.

A mysterious and ancient garden

Oregon is a state in the Northwest region of the US.

Orgrimmar is the orcish capital city

A TV Tower in Shanghai.

Orkney is an archipelago in northern Scotland and is the main location of Vertigo's "Northlanders" and "Crossed: Wish You Were Here".

A city in Florida famous for Disney World.

Orollan is a hidden city of Inhumans established by the Lor who separated from their brethren in Attilan.

World-city created by some philosophers as alternative to our own world which was too "materialistic" for them.

G.O.D. Satellite command center.

Third largest city in Japan. Capital of the Osaka Prefecture.

A prefecture in Japan. The capital is the city of Osaka.

Oscorp is a corporation run by Norman Osborn, also known as the Green Goblin. It was Oscorp's experiments on a spider that gave Peter Parker his arachnid abilities.

Oshawa is a city in Ontario, Canada, on the Lake Ontario shoreline.

Capital of Norway.

Ossus is a planet in the Star Wars comic books.

A Polish city infamous for being the location of Auschwitz.

Alternate Earth where two different versions of Supreme once met. Later the residence of Lady Supreme.

Magical realm

Otherspace is a dimension of untapped energy.

Annwn is the afterlife world in Welsh mythology and is ruled by the Celtic god Arawn.