Commonwealth Bank of Australia can trace its roots back to 1911 when it was established by the Australian government as a part of the Commonwealth Bank Act of 1911.
In 1920, the bank began acquiring central bank powers when it took over the responsibility for the issue of Australian bank notes from the Department of the Treasury.
During the 1940s, the bank had developed many branches across Papua New Guinea including Port Moresby, Boroko, Rabaul, Lae, Wau, Bulolo, Goroka, Kavieng, Madang, Mount Hagen, Kundiawa, Popondetta, and Wewak. On Bougainville, there was Kieta, Panguna, Arawa, and early on a part-time sub-branch at Loloho. It maintained those facilities to support trade, local business, government, and small savers.
Between 1991 and 1996 the Australian Government fully privatised the Commonwealth Bank.
The headquarters were moved to Tower 1, 201 Sussex Street, and two new nine-story buildings which were built at the site of the former location of the Sega World Sydney.
In August 2017, the financial intelligence agency, TRAC, launched civil proceedings in the Federal Court of Australia, alleging that CBA had breached money laundering and terrorism financing laws on 53,700 occasions. The bank stated that this was a computing error.