Harvey's duiker occurs in East African forests and thickets. It has rich red-brown fur, dark legs and facial markings, and a black crown tuft. Some taxonomies include it within the Natal duiker; sources that retain it separately describe a more northerly range and darker markings.
The 2025 specialist guide describes a medium-sized duiker weighing 10–14 kg, with rich red-brown fur, black or grey legs, a black facial line or blaze, and a black crown tuft. The extent and intensity of the dark markings vary among animals. Natal duiker is described as usually lacking the dark legs and having a smaller facial blaze.
Reported habitats include coastal forests and thickets, gallery forest, and montane forest including bamboo zones up to 2,400 m.
An extinction-risk assessment has not been added yet.