The Commonwealth Bank of Australia is an Australian multinational bank with businesses across New Zealand, Fiji, Asia, USA and the United Kingdom. Commonly referred to as the Commonwealth Bank (or CBA or Commbank), it provides a variety of financial services including retail, business and institutional banking, funds management, superannuation, insurance, investment and broking services. The Commonwealth Bank is the largest Australian listed company on the Australian Securities Exchange as of August 2015 with brands including Bankwest, Colonial First State Investments Limited, ASB Bank (New Zealand), Commonwealth Securities Limited (CommSec) and Commonwealth Insurance Limited (CommInsure). Commonwealth Bank is also the largest bank in the Southern Hemisphere.

Founded in 1911 by the Australian government, the Commonwealth Bank is one of the "big four" Australian banks, with National Australia Bank (NAB), ANZ and Westpac. The bank listed on the Australian Stock Exchange in 1991 and the government fully privatised it in 1996.