Korell is a planet in Foundation by Isaac Asimov. Located in the Whassalian Rift, it was the capital of the Republic of Korell. Korell was one of those frequent phenomena of a republic only in name. The dictator, called the Commdor 'first citizen of the state', is elected every year. Through some twist or another, a member of the Argo family is always chosen. According to Hober Mallow, people who didn't like this arrangement had '"'things'"' happen to them. According to Asimov, unlike a de jure monarch, the de facto monarchy associated with the status of the Commdor was not moderated by the typical influences of '"honour"' and '"court etiquette"'.

Korell was the third Seldon Crisis, because it was the first nation encountered by the Foundation with an effective system of nucleics. When Hober Mallow was sent to investigate. Mallow visited Asper Argo, Commdor of Korell, and opened up trade with his people through him. Despite discovering the steel foundries were not nuclear, Mallow did spot nuclear blasters provided by the Galactic Empire. Otherwise, Korell was decadent. The only remains of the Empire were ‘silent memorials’ and ‘broken buildings’; the navy consisted of ‘tiny, limping relics’ and ‘battered, clumsy hulks’.

Mallow later learned that the viceroy of the Normannic Sector was providing Korell with nuclear blasters and with ships (five by the time Korell declared war with the Foundation; a sixth was promised). Mallow quickly realised that the real enemy was the Empire, not Korell; forcing himself into the office of mayor, Mallow was able to destroy the threat of Korell by doing nothing. Since his visit three years before had made Korell dependent on Foundation-made goods, the Korellians raised a good deal of complaint over their minor inconveniences. Since there was no threat of foreign conquest, the people became rebellious. Faced by this situation, the Commdor was forced to surrender to the Foundation unconditionally.

The planets of the Korellian Republic eventually entered the Foundation's hands. They were captured briefly by Kalgan during the early stages of the war with Kalgan.