The Hawaiian–Emperor seamount chain is a mostly undersea mountain range in the Pacific Ocean that reaches above sea level in Hawaii.

It is composed of the Hawaiian ridge, consisting of the islands of the Hawaiian chain northwest to Kure Atoll, and the Emperor Seamounts: together they form a vast underwater mountain region of islands and intervening seamounts, atolls, shallows, banks and reefs along a line trending southeast to northwest beneath the northern Pacific Ocean.

The seamount chain, containing over 80 identified undersea volcanoes, stretches about 6,200 km (3,900 mi) from the Aleutian Trench off the coast of the Kamchatka peninsula in the far northwest Pacific to the Kamaʻehuakanaloa Seamount (formerly Lōʻihi), the youngest volcano in the chain, which lies about 35 kilometres (22 mi) southeast of the Island of Hawaiʻi.

Kamaʻehuakanaloa Seamount continues to grow offshore of Hawaiʻi island, and is the only known volcano in the chain in the submarine pre-shield stage.

[3] The second part of the chain is composed of the Northwestern Hawaiian Islands, collectively referred to as the Leeward isles, the constituents of which are between 7.2 and 27.7 million years old.

[4] On June 15, 2006, U.S. President George W. Bush issued a proclamation creating Papahānaumokuākea Marine National Monument under the Antiquities Act of 1906.

In 1963, geologist John Tuzo Wilson hypothesized the origins of the Hawaiian–Emperor seamount chain, explaining that they were created by a hotspot of volcanic activity that was essentially stationary as the Pacific tectonic plate drifted in a northwesterly direction, leaving a trail of increasingly eroded volcanic islands and seamounts in its wake.

If the hotspot had remained above a fixed mantle plume during the past 80 million years, the latitude as recorded by the orientation of the ancient magnetic field preserved by magnetite (paleolatitude) should be constant for each sample; this should also signify original cooling at the same latitude as the current location of the Hawaiian hotspot.

In addition to previous interpretations of the cause of the bend in the seamount chain, Hu et al. have proposed a close relationship between mantle plume migration and change in plate tectonic motion.

Expanding on previous models, it has been interpreted that the Pacific Plate's motion was predominantly in the northern direction prior to 47 million years ago.

The combination of these events along with new subduction zones in the west, could explain the large bend present in the Hawaiian - Emperor Seamount Chain.

The chain has been produced by the movement of the ocean crust over the Hawaiʻi hotspot, an upwelling of hot rock from the Earth's mantle.

As the oceanic crust moves the volcanoes farther away from their source of magma, their eruptions become less frequent and less powerful until they eventually cease altogether.