The Farn were a species, at least some of whom were assimilated by the Borg prior to 2368.

A number of Farn drones found themselves liberated from the Borg Collective on a planet in the Nekrit Expanse, and quickly raided the Parein. (VOY: "Unity")

This species was only mentioned in dialogue.
According to Star Trek: Star Charts (p. 87), there was a star system named Farn, which might possibly be the system of origin for this species, in the Delta Quadrant. The system's primary was a G-class star.
Community content is available under CC-BY-NC unless otherwise noted.