The dentate gyrus (DG) is part of the hippocampal formation in the temporal lobe of the brain, which also includes the hippocampus and the subiculum. The dentate gyrus is part of the hippocampal trisynaptic circuit and is thought to contribute to the formation of new episodic memories, the spontaneous exploration of novel environments and other functions.

It is notable as being one of a select few brain structures which may have significant rates of adult neurogenesis in many species of mammals, from rodents to primates. Other sites of adult neurogenesis may include the subventricular zone, the striatum and the cerebellum. However, whether significant neurogenesis exists in the adult human dentate gyrus has been a matter of debate.