The red-bellied titi monkey or dusky titi (Plecturocebus moloch) is a species of titi monkey, a type of New World monkey, endemic to Brazil. It lives in forests and thickets.

It has a rounded head and a thick, soft coat and frequently adopts a characteristic posture with the body hunched, limbs close together, and a tail hanging down. The body is 28–39 cm (11–15 in) long, and the tail is 33–49 cm (13–19 in).

It can move quite fast if necessary but rarely does so and generally stays within a fairly small area, feeding on fruit, insects, spiders, small birds, and bird's eggs. It is diurnal and moves in pairs or family groups, which communicate by means of a wide repertoire of sounds. The female gives birth to a single offspring.