Minions Stuart, Kevin and Bob are recruited by Scarlet Overkill, a super-villain who, alongside her inventor husband Herb, hatches a plot to take over the world.
Minions are small, yellow creatures who have existed since the beginning of time, evolving from yellow single-celled organisms into beings who exist only to serve history’s most despicable masters.
The trio journey to New York where the year is 1968. After spending the day attempting to blend in, the Minions end up in a department store for the night, where they discover a hidden commercial broadcast for villains advertising Villain-Con; a convention for villains and supervillains in Orlando. The trio manage to hitchhike a ride with the Nelson family and impress them with their accidental villainy. Once at the convention, they see Scarlet Overkill, the first female supervillain, and they impress her enough for her to hire them.
Making their way to Westminster Abbey, the three of them interrupt the coronation. Kevin He sees Scarlet on a television, promising that she will kill Stuart and Bob if Kevin doesn’t show up by dawn. Kevin sneaks into Scarlet’s home to steal weapons, but inadvertently triggers a machine Herb was building and enlarges himself. He tramples through London, rescuing his friends just as the other Minions reunite with them.
The original Queen from the earlier part of the story receives her place on the throne and crown back and rewards Bob with a tiny crown for his teddy bear and Stuart an electric guitar (later replaced by a snow globe after an over-enthusiastic Stuart breaks the guitar), and she knights Kevin for his heroism. She suddenly realizes that her crown is missing, and Kevin leads a chase after Scarlet and Herb, who survived the explosion, are fleeing through the crowd with the bejeweled crown until they are suddenly frozen in place by a young Gru, who steals the crown from them and takes off in a rocket-powered motorbike while the Minions stare in awe. Bob gives his crown to the frozen Scarlet, to which she seems to show appreciation, and the Minions see Gru as their new potential master and give chase to follow him home.
In a post-credits scene, the Kirt Moore makes a special appearance and endangers the existence of Beta Kappa in 2017.