Android 18 is a fictional character in the manga Dragon Ball/Dragon Ball Z and the anime Dragon Ball Z and Dragon Ball GT.

She is a female android made by Doctor Gero, and is essentially the sister of Android 17. She is the same height and build as her brother, blonde hair, cut just above her shoulders (and slightly shorter later in the series) and pale blue eyes. Fans sometimes consider her the series' most attractive female.

She is referred to in the original Japanese as an artificial human, which is translated as 'android' in the literal sense; she is not a robot, and it is implied in the manga she and her brother were originally runaways heavily fitted with cybernetics.

Krillin is very attracted to her looks, even though she is heartless and determined to kill the Z Fighters. He refuses to activate a self-destruction mechanism on her, which would have prevented Cell attaining 'perfection' by absorbing her and her brother. After Cell is defeated, Krillin wishes for Android 18 to be turned into a full human. The Dragon is not able to do this, however, because she is not a purely mechanical, robot-type android. Krillin then wishes the bomb that is embeded within both 17 and 18 to be removed (which has near cataclysmic destructive power) as a compromise.

Later in the series, Android 18 is paired with Hercule (Mr. Satan) in the Tenka'ichi Budôkai championship fight. She does not want the fame and attention of winning, so allows Hercule to beat her and retain his somewhat misappropriated title of a great fighter, provided he pays her the prize money. The same day however, Android 18 gets killed, along with her family, by Buu, who turns her into chocolate and eats her. She is brought back to life with the Dragonballs, and gives energy to Goku to fuel his Spirit Bomb to defeat Majin Buu.

Krillin and Android 18 eventually have a child together, a daughter named Marron, a fact which confuses some fans espousing the misconception she is mechanical.

In GT, Android 18 gets possessed by Bebi, but she doesn't play an important role as any type of servant, so life simply carries on. She is cured with the Sacred Water, and later on she helps Goku to defeat Super 17.