Leptomithrax gaimardii is a species of crab in the Majidae family, first described by Henri Milne-Edwards in 1834 as Paramithrax gaimardii, from a specimen found in New Zealand waters by Joseph Paul G

Joseph Paul Gaimard was a French naval surgeon, naturalist, and explorer. He served as a scientific officer on French voyages to the Pacific Ocean and the Arctic region.