To those who still insist that the main character should be named Shidou Maria because the title has Maria in it, please jump off a cliff.
This and this should make it very obvious that his name is Mariya in English.
The “Maria” from the title comes from 聖母マリア (Seibo Maria), who we call the Holy Mother Mary in English.
There isn’t a Maria running around in Maria-sama ga Miteiru either.