Nanochromis transvestitus is a sexually dimorphic cichlid endemic to Lake Mai-Ndombe in the Democratic Republic of the Congo where they live at a depth of around 1 metre (3.3 ft).

The female has a vertical black and white banding on her anal and caudal fins, with a bright red abdomen.

Like many cichlids, the male does, however, have longer anal and caudal fins.

This species is particularly threatened by the practice of using mosquito netting to catch fish out of the lake as material with holes that small catches every species of fish in the lake regardless of size.

[1] The specific name is a derived from the Latin trans meaning "cross" or "over" and vestitus meaning "clothed", a reference to the reversal of the normal sexual dimorphism in that this species has drabber males and more colourful females.