The Bay of Biscay is a gulf of the northeast Atlantic Ocean located south of the Celtic Sea. It lies along the western coast of France from Point Penmarc'h to the Spanish border, and along the northern coast of Spain, extending westward to Cape Ortegal. The southern area of the Bay of Biscay that washes over the northern coast of Spain is known locally as the Cantabrian Sea.

The Atlantic Ocean is the second-largest of the world's five oceans, with an area of about 85,133,000 km2 (32,870,000 sq mi). It covers approximately 17% of Earth's surface and about 24% of its water surface area. During the Age of Discovery, it was known for separating the New World of the Americas from the Old World of Afro-Eurasia.