This is a list of islands in the Atlantic Ocean, the largest of which is Greenland. Note that the definition of the ocean used by the International Hydrographic Organization (IHO) excludes the seas, gulfs, bays, etc., bordering the ocean itself. Thus, for instance, not all of the islands of the United Kingdom are actually in or bordering on the Atlantic. For reference, islands in gulfs and seas are included in a separate section. Oceanic islands are formed by seamounts rising from the ocean floor with peaks above the surface of the ocean and are not parts of continental tectonic plates.