Why did Malcolm X call himself Malcolm X?

Answer 1

The Nation of Islam was a group in which Malcolm little joined. This groups members rejected their slave surnames (little) and replaced it with a 'X'.

Therefore Malcolm X.

Hope this helps

Answer 2

Malcolm Little changed his name to Malcolm X after he joined the Nation of Islam who believed that African American's names were not their true family names. Their school of thought was that these were the names of their ancestors slave owners and not their true names so they gave themselves the name X meaning unknown.