Gnathochromis pfefferi is an African species of fish in the family Cichlidae.

It is endemic to Lake Tanganyika and its slow-flowing tributaries in the countries of Burundi, the Democratic Republic of the Congo, Tanzania and Zambia.

[1] This cichlid is found in relatively shallow waters, typically over soft bottoms in places with aquatic grasses.

[3] Although currently included in the genus Gnathochromis, it is distantly related to the type species G. permaxillaris (tribe Limnochromini), instead being closer to Tropheini.

[5] The specific name honours the German zoologist Georg Johann Pfeffer (1854-1931).