Howell 320 was a planet in or near the space of the Federation, somewhere in the Alpha or Beta Quadrant.

The Starfleet starship USS Repulse was travelling towards Howell 320 in 2367, carrying a pair of Federation ambassadors who hoped to end a civil war on the world. The Repulse was held away from that mission by the presence of a planet killer weapon entering the nearby Kalish system. (TNG novel: Vendetta)