Originally Posted by James_Smith
I thought it is his surname in the movie universe? His father (who he killed) was Thomas Logan, right?
Yeah, but the only place that was shown was in the end credits. There was no place in the movie itself where he took that name. In the Origin comic, it was his friend Rose that said his name was Logan when they got jobs at a mine, because she couldn't use his real name and Logan was the first name she thought of.
The other movies only used Logan as his name, but never said whether it was his first or last name (and X1 was before Origin was published, I believe). The prequel could have at least sorted out his name.