Ktarians are an alien species native to the Alpha Quadrant. They are recognized by their catlike eyes and large frontal skull bones. Ktarians mature much faster than other species of their region of space - Naomi Wildman, half Ktarian, appeared to age at over double the rate of humans.

In 2368 , a Ktarian plot to take control of Starfleet was uncovered when a mercenary named Etana Jol was captured while attempting to spread a mind-controlling device throughout the fleet. However, Etana was clearly not Ktarian, and may have been simply acting on behalf of a splinter group of renegades - this is supported by later episodes which describe the Ktarians joining the United Federation of Planets.

The seventh planet in the Ktarians' home star system is used by their race as a sacred burial ground - Ktarians will lay thousands of stones on the graves, each stone representing a special prayer.

Ktarian cuisine is also well known throughout the galaxy. Noted Ktarian desserts include the Ktarian chocolate puff and spice cake; Ktarian eggs are highly sought after as a breakfast dish.