Cephalophus castaneus is a forest antelope ranging from southern Cameroon through southern Central African Republic and eastern DR Congo to northern Angola. Its reddish-chestnut coat has a broad dark stripe along the back, and fruit is its main food.
The coat is rich reddish chestnut. A black dorsal band runs from the neck to the rump, broadens over the back and narrows to a line on the tail. All four legs are dark brown; the throat and upper neck are whitish. The black tail has white borders and a white tip. The face bears a reddish blaze and crown tuft. Both sexes have smooth, parallel horns, with longer horns in males.
It prefers closed-canopy forest and is found most often in moist lowland areas. In stomach-content analysis of 51 individuals, fruit averaged 86.3% of the diet by dry weight and leaves 11.1%. Leaves were eaten more often in March–May, the short rainy season, than at other times.
An extinction-risk assessment has not been added yet.