- For the primary universe counterpart, see Qo'noS.
| PLANET | |
| Qo'noS' | |
 Qo'noS, as it appeared in the mid 22nd century | |
| Full name: | Qo'noS |
| Alternate name(s): | Kling |
| Classification: | Class M |
| Affiliation: | Klingon Empire |
| Location: | Beta Quadrant |
| Moon(s): | Corvix, Praxis (destroyed in 2294) |
| Dominant Species: | Klingons |
| Warp Capable: | 930 AD |
| Capital: | First City |
| |
In the dark mirror universe, Qo'noS, (or Kronos in English) also known as Kling, was the homeworld of the Klingon species and capital planet of the Klingon Empire, located in the Klinzhai system, until it was destroyed by forces of the Terran Empire in 2294 which ended the Terran-Klingon War.
The world orbited an orange bright sub-giant (Type K1 IV) star and possessed two moons: Corvix and Praxis, until those moons were destroyed after the destruction of Qo'noS in 2294. The planet itself possessed a single landmass that comprised the entire habitable surface. The terrain consisted primarily of high, rocky mountains, jagged cliffs, and rivers of lava, which were the result of unstable tectonics. A greenhouse effect caused by the volcanic ash kept the planet's surface warm and trapped its oxygen-nitrogen atmosphere. The interaction of cold air over the ocean and extremely hot air over the continents gave rise to sizable storms; with no land on the planet's far side to halt their growth, hurricanes the size of Earth's North America formed over the sea and slammed into the land like a sledgehammer. Visitors to Qo'noS found it difficult to move around in the high gravity (1.23G) and thick atmosphere causing fatigue among those who visited the planet.
Out of the other five planets in the system, Qo'noS was the only habitable Class M planet, though it required a certain level of technology in order to maintain the environment.