Walter Elias Disney and Michael Theodore Mouse. Mickeys original name was Mortimer, Walts wife Lillian disliked the name so she named him Michael because she liked it better, and an icon was born, Mickey Mouse. If Lillian hadn't spoke up we would have grown up watching Mortimer Mouse. Lillian was right, I like Mickey so much more. If not for Walts pet mouse he had as a child, there would be no Mickey at all. MIC KEY MOUSE.