Amblymelanoplia castanea is a species of beetle of the family Scarabaeidae. It is found in South Africa.
Adults reach a length of about . They are dull blackish red-brown, with the head and pronotum black and the antennae red-brown. The clypeus and head have brown setae. The pronotum has brown setae and some white scales at the posterior margin. The elytra have brown setae.
The species name is derived from Latin castane (meaning chestnut) and refers to the colour of the species.