Nemichthys larseni is an eel in the family Nemichthyidae. It was described by Jørgen G. Nielsen and David G. Smith in 1978. It is a marine, deep water-dwelling eel which is known from the eastern Pacific Ocean, including Oregon and Hawaii, USA, Mexico, and the Gulf of California. It dwells at a depth range of 0 to 1,000 metres. Males can reach a maximum total length of 161 centimetres (63 in).