They are one of the most popular sweets in the world but many fans are only just finding out what M&M's stands for.
The Daily Mail reported that despite the hard shell-covered chocolate being created in 1941 and becoming a popular treat, the reason for the name has been a mystery to many people.
While some believed it was inspired by the 'mmm' sound made when eating the chocolate, the truth behind the name is actually quite simple.
Created by Forrest E. Mars Sr, who started Mars, and Bruce Murrie, a post on Reddit revealed the M&M name are the initials of their last names, Mars and Murrie.