The O2 Arena, commonly known as The O2, is a multi-purpose indoor arena in the centre of The O2 entertainment district on the Greenwich Peninsula in southeast London.

VMED O2 UK Limited, trading as Virgin Media O2, is a British mass media and telecommunications company based in London, England.

(formerly known as The Millennium Dome) a large entertainment district on the Greenwich peninsula in South East London, England, including an indoor arena, a music club, a Cineworld cinema, an exhibition space, piazzas, bars, restaurants, and a guided tour to the top of the O2.

The O2 is an entry-level Unix workstation introduced in 1996 by Silicon Graphics, Inc. to replace their earlier Indy series.