Walter Baldock Durrant Mantell (11 March 1820 – 7 September 1895) was a 19th-century New Zealand naturalist, politician, and land purchase commissioner.

[1] In 1848, Mantell was appointed to the office of commissioner for extinguishing native titles in the South Island.

[2] After his father committed suicide in 1852,[3] much of his collection of fossils was inherited by Walter and consequently transported to New Zealand.

[4] Mantell left New Zealand as he did not feel right about trying to convince the indigenous Māori people to undersell their land and returned to England in 1856, where he met Geraldine Jewsbury, a woman eight years his senior.

[7] In 1865, he donated the "prime specimen" of his father's fossil collection to Wellington's Colonial Museum (modern-day Museum of New Zealand Te Papa Tongarewa), including the famous tooth that had led to the discovery of Iguanodon.

[11] Mantell's fossils remain in possession of the Museum of New Zealand to the present day.