From Wikipedia (Star Trek: The Animated Series)
Star Trek: The Animated Series is an animated science fiction television series set in the Star Trek universe following the Star Trek: The Original Series of the 1960s. The animated series was aired under the name Star Trek, but it has become widely known under this longer name (or abbreviated as ST: TAS or TAS) to differentiate it from the original live-action Star Trek. The success in syndication of the original live action series and fan pressure for a Star Trek revival led to The Animated Series from 1973–1974, as the source of new adventures of the Enterprise crew, the next being the 1979 live-action feature film Star Trek: The Motion Picture. TAS was the first Star Trek series to win an Emmy Award.
I’m a huge Trek fan, so feel free to discuss the Animated Series to its finest minutiae or anything else you desire.
By the way, regarding TAS’s canon status, as far as I am concerned, its canon.