Kes is a character in the Star Trek fictional universe, played by Jennifer Lien in the television series Star Trek: Voyager.

Kes was an Ocampan, an elf-like race native to the Delta Quadrant, with a lifespan only 1/10 that of humans—approximately nine years. She was taken on board the USS Voyager crew with her partner, Neelix. Kes had mysterious metaphysical powers that were relatively unknown, even to herself, that she developed with the aid of Tuvok.

Kes developed a close relationship with the Doctor during her time as an assistant medical technician.

In the episode "Warlord", she treated an Ilaran man carrying the consciousness of former Ilaran tyrant Tieran, who transferred himself into Kes and exploited Kes's telekinetic powers for his own goal of re-conquering Ilara. After Tieran entering her mind but before anyone realizing it, she broke up with Neelix, then proceeded to steal a shuttlecraft to go to Ilara. After being rescued and having Tieran purged from her mind, Kes was somewhat traumatized. Tuvok told her that she'd have to learn and adapt from the experience and that she'd never be quite the same again.

In an alternate timeline in the episode "Before and After", Kes stayed on Voyager through the ship's yearlong battle with the Krenim, becoming infected with chronitons from a temporal weapon. Kes married Tom Paris, and they had a daughter Linnis, who married Harry Kim and bore Andrew, grandson of Kes. At this time, Kes was nine years old and ready to accept death at an age normal for Ocampans. The Doctor, however, was not, so he devised a biotemporal chamber which had the unintentional effect of reactivating chronitons dormant in Kes's body and sending her on a backwards journey through time all the way back to her birth. Kes was able to let the Doctor in the third season part of the timeline what was happening to her and the frequency of the torpedo, leading to the Doctor devising a treatment and restoring Kes to temporal sync. Once she was back to normal, she "prophecied" to the Captain about the fourth season episode "The Year of Hell".

She left the Voyager crew when she "evolved" into a different state, but before leaving she threw Voyager 20 years closer to Earth ("The Gift"). She visited Voyager once more, in a story involving time travel ("Fury"). At this point she appeared much older than she had earlier. This episode ended with her taking her ship back to Ocampa.

Kes's ultimate fate has yet to be revealed. It's unknown whether or not her evolution extended her life span. If her life span was not extended, she would have been elderly by the time Voyager returned to Earth.