Joseph Gilbert Seamount is a large seamount in the Tasman Sea located 450 km (280 mi) west of the South Island of New Zealand at the southern edge of the Lord Howe Rise.

[1][2] It has an elongated northwest–southeast trend, covering an area of about 11,500 km2 (4,400 sq mi) and rising to 2,400 m (7,900 ft) below sea level.

[2] The seamount is a continental fragment that rifted away from the South Tasman Rise and Challenger Plateau during the Cretaceous breakup of Gondwana.

[2][3] It is separated from the easterly Challenger Plateau by a 4,400 m (14,400 ft) deep saddle.

[2] Joseph Gilbert Seamount is named after Joseph Gilbert, captain of HMS Resolution (1771) on the second voyage of James Cook,[1] and has been known under a variety of names throughout its history, including Gilbert Ridge, Gilbert Seamount Complex and Gilbert Seamount.