Outpost Caleb IV was a Federation outpost on the planet Caleb IV in the 23rd century.
In the 2260s, it was the site of the Battle of Caleb IV. It was attacked by two Klingon divisions led by Kang and Kor. Aboard the D7 class cruiser IKS Klothos, Kor outmaneuvered the defending Federation forces by attacking with an initial feint, and then returning with his full force, catching the Federation in the midst of their repair work. However, the Klingons were driven off by the USS Lexington, which brought relief supplies for the outpost. Overall, the battle was known as one of the most humiliating defeats of the Federation-Klingon Cold War.
A century later, during a similar attack on a Dominion base at Trelka V, Kor believed that he was back at Caleb IV.