Jonah Hill is gunning to legally change his name, but you won't need to call him anything different -- it just means lots of paperwork for him ... or his assistant.
According to docs, obtained by TMZ, the actor -- whose real name is Jonah Hill Feldstein -- filed a petition this week in L.A. to legally drop Feldstein from his name. So, he's just making his stage name official.
The docs say Jonah simply wants the name he's publicly gone by for years to be his legal handle. It is all the rage these days.