Lieutenant Commander Data is a fictional character in the Star Trek franchise. He appears in the television series Star Trek: The Next Generation (TNG) and the first and third seasons of Star Trek: Picard; and the feature films Star Trek Generations (1994), First Contact (1996), Insurrection (1998), and Nemesis (2002). Data is portrayed by actor Brent Spiner.

Data was found by Starfleet in 2338. He was the sole survivor on Omicron Theta in the rubble of a colony left after an attack from the Crystalline Entity. He is a synthetic life form with artificial intelligence, designed and built by Doctor Noonien Soong in his own likeness (likewise portrayed by Spiner). Data is a self-aware, sapient, sentient and anatomically fully functional male android who serves as the second officer and chief operations officer aboard the Federation starship USS Enterprise-D and later the USS Enterprise-E.

His positronic brain allows him impressive computational capabilities. He experienced ongoing difficulties during the early years of his life with understanding various aspects of human behaviour and was unable to feel emotion or understand certain human idiosyncrasies, inspiring him to strive for his own humanity. This goal eventually led to the addition of an "emotion chip", created by Soong, to Data's positronic net. Although Data's endeavor to increase his humanity and desire for human emotional experience is a significant plot point (and source of humor) throughout the series, he consistently shows a nuanced sense of wisdom, sensitivity and curiosity, garnering respect from his peers and colleagues.

Data is in many ways a successor to the original Star Trek's Spock (Leonard Nimoy), in that the character has superior mental skills and offers an "outsider's" perspective on humanity.