In the anatomy of mammals, the hypothalamus is a gland located below the thalamus region of the brain, forming the major portion of the ventral region of the diencephalon and functioning to regulate certain metabolic processes and other autonomic activities. The hypothalamus links the nervous system to the endocrine system by producing releasing hormones.

In particular, the hypothalamus is the area of the brain that controls body temperature, hunger, and thirst.

See also limbic system, HPA axis