Gobius tetrophthalmus is a species of marine fish from the family Gobiidae, the true gobies. It occurs in the Atlantic Ocean around Cape Verde, western Africa, where it is found at depths from 7mto25mm (23feetto82feetm). It prefers areas with coralline algae though it will also inhabit areas with substrates of sand and rock. This species can reach a length of 7.8cm (03.1inches) TL. It is harmless to humans.