Alpha Bank is the second largest bank in Greece after National Bank of Greece, with 450 branches throughout the country. It also has a subsidiary and branch in London, and branches and subsidiaries throughout the Balkans (see "International expansion" below). Founded in 1879, it has been controlled by the Costopoulos family since the very beginning. Currently the bank is chaired by Ioannis Costopoulos, who is the grandson of the original founder John F. Costopoulos, and the nephew of Stavros Costopoulos, Foreign Minister in the liberal government of Georgios Papandreou.^{[citation needed]}

In the early 1990s, the bank started on a program of international expansion, especially in the Balkans.

In addition, Alpha Bank has a branch in London and a finance company, Alpha Finance US, in New York.