The Black Sea Trade and Development Bank (BSTDB) is multilateral development bank serving the eleven countries that are members of the Organization of the Black Sea Economic Cooperation, a regional economic organization. It supports economic development and regional cooperation by providing trade and project financing, guarantees, and equity for development projects. BSTDB supports both public and private enterprises in its member countries and does not attach political conditionality to its financing.

Objectives of the bank include promoting regional trade links, cross country projects, foreign direct investment, supporting activities that contribute to sustainable development, with an emphasis on the generation of employment in the member countries, ensuring that each operation is economically and financially sound. The bank has an authorized capital of EUR 3.45 billion.

BSTDB is governed by the Agreement Establishing the Black Sea Trade and Development Bank, a United Nations registered treaty. The Agreement came into force on January 24, 1997. BSTDB commenced its operational activities in June 1999.