Led by the United Kingdom and France, nine nations met at the Nyon Conference to address international piracy in the Mediterranean Sea.

The Nyon Conference was a diplomatic conference held in Nyon, Switzerland, in September 1937 to address attacks on international shipping in the Mediterranean Sea during the Spanish Civil War. The conference was convened in part because Italy had been carrying out unrestricted submarine warfare, although the final conference agreement did not accuse Italy directly; instead, the attacks were referred to as "piracy" by an unidentified body. Italy was not officially at war, nor did any submarine identify itself. The conference was designed to strengthen non-intervention in the Spanish Civil War. The United Kingdom and France led the conference, which was also attended by Bulgaria, Egypt, Greece, Romania, Turkey, the Soviet Union and Yugoslavia.