Starbase 336 was a Federation starbase administered by Starfleet.

In 2365, this base received an automated transmission from the 23rd century Klingon battle cruiser IKS T'Ong. The transmission stated the ship was returning home and would be reaching the awakening point. Starfleet Command was subsequently notified. (TNG: "The Emissary")

This starbase was only mentioned in dialogue.
According to Stellar Cartography: The Starfleet Reference Library ("Federation Historical Highlights, 2161-2385"), Starbase 336 was located in the Beta Quadrant.