The National Bank of Greece (NBG; Greek: Εθνική Τράπεζα της Ελλάδος) is a global banking and financial services company with its headquarters in Athens, Greece.

85% of the company's pretax preprovision profits are derived from its operations in Greece, complemented by 15% from Southeastern Europe. The group offers financial products and services for corporate and institutional clients along with private and business customers. Services include banking services, brokerage, insurance, asset management, shipping finance, leasing and factoring markets. The group is the largest Greek bank by total assets and the third largest by market capitalisation of €1.06 billion as at 4 December 2018. It is the second largest by deposits in Greece after Piraeus Bank. It is fourth largest by Greek loan assets trailing Piraeus Bank, Alpha Bank and Eurobank Ergasias.

The bankers Jean-Gabriel Eynard and Georgios Stavros founded NBG in 1841 as a commercial bank. Stavros was also elected as the first director of the Bank until his death in 1869. From NBG's inception until the establishment of the Bank of Greece in 1928, NBG enjoyed the right to issue banknotes. When the Athens Stock Exchange was founded in 1880, NBG immediately listed on the exchange, a listing it has retained to the present.

The bank is currently listed on the Athens Exchange (Athex: ETE, ISIN GRS003003019); it is a constituent of the FTSE/Athex Large Cap index. From 1999 to 2015 it was listed on the New York Stock Exchange (NYSE:NBG, ADR, ISIN US6336437057).