If I created a character's name and it just so happened there was already the same name used in a movie, can I still use that name?

I wish you had more details. Obviously you didn’t “create” the name as it already exists. But most things are machinations of other things, anyway. SO, it depends – would be my answer. Copyright laws DEF do exist! The ‘depends’ part is whether the name you like is, say, “Shrek.” Def copyright issue. “Superman.” “Garfield.” Same thing. However if you’re choosing, “Lola,” say or “Pig,” well…... that’s hardly a ‘stolen’ name. Hope that helps.

If when you say the character’s name, people can identify it from another story > copyright. Plus, why would you want that name, anyway? Pick another name!

Names in a work of fiction are not copyrighted but if it is a name that is so intensely and inextricably connected with another character, you might want to reconsider the name of your character. It’s just that it probably isn’t a very good idea to have a character named Holden Caufield, or Harry Potter or Sherlock Holmes, or Jane Eyre or Huckleberry Finn if you get my drift. It’s not copyrighted, but unless you have some particular reason supported by the narrative to have a character with a famous fictional name, it’s just not a good idea.

Forest Gump, Jerry Seinfeld, yes, I’d change it. If it is immediately recognizable, change it.

You’ll find some pertinent comments here in this question asked two days ago.

Actually, there are many legal cases around IP “Intellectual Property.” It can cover anything that’s a result of creativity. It includes the physical expression of ideas – fiction or non – contained in books, plays, moves, etc. It’s…. Intellectual Property.

There is no law that says two people can’t have the same name.

I used to work with a man who had a really unusual name. I’d never even run across anyone with his first name before. I remarked to him once, “I bet you don’t run into many people with the same name as you.” He said, “Are you kidding? There’s a musician right here in this city, a woman, who has the same name as mine, first and last.” I Googled his name, and yes, there was.

The movie The Producers has the accountant named Leopold Bloom. That name is shared by the lead character in Jame Joyce’s Ulysses.
Don’t worry about it. If you are successful enough for it to become an issue, you will have made a fortune.

thanks you all