Mount Kyllini or Mount Cyllene (Greek: Κυλλήνη), is a mountain on the Peloponnesus peninsula in Greece. It rises to 2374 m (7789 ft) above sea level, and is located near the border between the historic regions of Arcadia and Achaea, in the northeast of Arcadia.

In Greek mythology, Hermes is said to have been born in a cave on the mountain, and so Cyllenius is a frequent epithet of his. In ancient times there was reported to be a temple and statue dedicated to him on the mountain's summit.

There are also several nearby places named Kyllini.