O2 Arena may refer to:

• The O2 Arena (London)
• O2 Arena (Prague)
• O2 World (Berlin)
• O2 World (Hamburg)

The O₂ Arena, referred to as North Greenwich Arena in the context of the 2012 Summer Olympics and 2012 Summer Paralympics, is a multi-purpose indoor arena located in the centre of The O2, a large entertainment complex on the Greenwich Peninsula in London. It is named after its main sponsor, the telecommunications company O2.