In fact, Mickey Mouse was born with another name.
Seeking a replacement for Oswald the Lucky Rabbit in 1930, Walt Disney and his partner Ub Iwerks came up with a mouse—Mortimer Mouse. At the suggestion of Disney’s wife Lillian, they later changed the mouse’s name to Mickey.
Mickey Mouse made his debut in 1928 in an animated short called “Steamboat Willie” and continues to star in countless animations. Mortimer Mouse, however, did make appearances later in other works as Minnie’s uncle.