For the 24th century Klingon officer, please see Klag (Lieutenant).
Klag was the Klingon governor of a secured star system in 2154.
That year, Enterprise NX-01 passed through while in pursuit of a Klingon Bird-of-Prey commandeered by Augments. Klag had ordered that all ships traveling through the system be inspected. When informed of this, Jonathan Archer claimed that he didn't take orders from a mere governor. (ENT: "The Augments")
This character was only mentioned in dialogue.