"Mudd's Passion" is the tenth episode of the first season of the animated science fiction television series Star Trek. It first aired in the NBC Saturday morning lineup on November 10, 1973, and was written by Stephen Kandel who wrote the previous "Mudd" episode, the Original Series's "I, Mudd", as well as the teleplay for Gene Roddenberry's first "Mudd" episode, "Mudd's Women".

In this episode, the Enterprise brings aboard con-artist Harry Mudd who spreads a fast-acting love potion on the ship. The story features actor Roger C. Carmel voicing an uncredited reprise of his live-action role as Harry Mudd.

On stardate 4978.5, the starship Enterprise receives orders to arrest Federation outlaw Harry Mudd, who is accused of selling fake love-crystals. Intercepting Harry on the mining colony of Motherlode, they bring him aboard the Enterprise. Harry explains that he was able to escape the custody of the android planet by teaching the androids how to play organized sports. While the entire planet population was cheering on their respective teams at a baseball game, Mudd slipped away.

However, after convincing Nurse Chapel to try and use the love-crystals to win the affection of the Vulcan Science Officer, Mr. Spock, Mudd abducts her, steals a shuttlecraft, and escapes to a rocky planet. The love-crystals, however, have affected Spock, who pursues him to the planet, accompanied by Captain Kirk.

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