Au contraire, the Three Musketeers are actually considered to be a foursome: Athos, Porthos, Aramis, and D'Artagnan, with D'Artagnan being the "fourth musketeer" who joins the other three throughout the story.
“ “Wherever there is injustice, you will find us. Wherever there is suffering, we’ll be there. Wherever liberty is threatened, you will find... The Three Amigos!”.
”
Three’s Company (Jack, Janet, and Chrissy)
The Three Stooges (Moe, Larry, and Curly)
The Three Amigos (Steve Martin, Chevy Chase, and Martin Short)
The Three Bears (From the fairy tale Goldilocks and the Three Bears, Papa Bear, Mama Bear, and Baby Bear.