What planet are the Klingons from?

The Klingons are from Qo'noS, the traditional homeworld of the Klingon species and the capital world of the Klingon Empire.

Qo'noS is also rendered in English as Kronos. The name “Kronos” appears in Star Trek VI: The Undiscovered Country, while “Qo'noS” is the Klingon-language transliteration later popularized in Star Trek reference material and television dialogue. It is usually pronounced roughly like “Kronos.”

The planet is associated with the Klingons' warrior culture, imperial government, and capital city. Praxis, Qo'noS's moon, was destroyed in Star Trek VI, creating a major political and environmental crisis for the Empire.

A modern continuity development complicates the wording slightly: Star Trek: Starfleet Academy establishes that Qo'noS was destroyed and that the Klingons later settled on Faal Alpha. However, Qo'noS remains the canonical ancestral homeworld and the standard answer to this classic trivia question.