Cryptolarynx marshalli is a species of beetle of the family Curculionidae. It is found in South Africa, where it is only known from the Western Cape Province.
Adults reach a length of about 2.5âÂÂ2.9 mm and have an integument black body, with the antennae, tibiae and tarsi reddish.
Specimens were collected in July at the base of Oxalis imbricata.
This species is named in honour of weevil expert Sir Guy A.K. Marshall, who described the genus and its original two species and discussed its unique characters among known weevils.