Star Trek: The Animated Series (TAS) is an American animated science fiction television series created by Gene Roddenberry. It originally aired simply under the title Star Trek, subtitled Created by Gene Roddenberry, on Saturday mornings from September 8, 1973 to October 12, 1974 on NBC, spanning 22 episodes over two seasons. The second series in the Star Trek franchise, it features mostly the same characters as Star Trek: The Original Series. Set in the 23rd century, the series follows the further adventures of the Starship USS Enterprise as it explores the galaxy.

After the cancellation of The Original Series (TOS) in 1969, the live-action show proved popular in syndication and generated significant fan enthusiasm. This resulted in Roddenberry's decision to continue the series in animated form. Much of the original cast returned to provide voices for their characters. Series writers David Gerrold and D. C. Fontana characterized The Animated Series as effectively a fourth season of The Original Series. After the conclusion of The Animated Series, the adventures of the characters continued in live-action theatrical films, beginning with the 1979 film Star Trek: The Motion Picture.

The Animated Series was critically acclaimed and was the first Star Trek series to win an Emmy Award when its second season received the 1975 Emmy for Outstanding Entertainment – Children's Series.