In anatomy of mammals, the telencephalon (or cerebrum) is a part the brain. The telencephalon is the top of the brain, and is the most developed in phylogenetically younger species.

In humans, the telencephalon surrounds older parts of the brain much like a helmet or turban. The telencephalon includes the cerebral cortex of the cerebral hemispheres, a limbic lobe and an olfactory lobe. Limbic, olfactory and motor systems project fibers from subcortical areas of the cerebrum to parts of the brainstem. Cognitive and volitive systems project fibers from cortical areas of the cerebrum to thalamic nuclei and to other regions of the brainstem.

Cortical lobes of the cerebral hemisphere shown in red, orange, yellow and green

In humans, neural networks of the telencephalon facilitate complex learned behaviors, such as the use of language. The telencephalon emerges from the prosencephalon, which is the most rostral of three vesicles that form from the embrionic neural tube.

The telencephalon includes regions of archipalliar, paleopalliar and neopalliar origin. Profound development of the neopallium, which comprises the cerebral cortex, is unique among humans, and Old World Monkeys.

See also: Regions in the human brain