Obi Island Melomys is recorded in lowland forest on Obi Island, Indonesia. It is thought to spend most of its time in trees.
It has a reddish back, a white underside, small feet, and a tail longer than its head and body.
It is considered mostly arboreal, and it was observed eating Piper aduncum fruit up to 3 m above the ground. Some individuals were also trapped on the ground among rocks and ferns by a creek.
Head-and-body length is 123–129 mm, and tail length is 148–175 mm.
Body weight is 68–74 g.
An extinction-risk assessment has not been added yet.