Is Minnie Mouse public domain?

Excuse me, could you please clarify something for me? I've been hearing a lot about Minnie Mouse and I'm wondering if she's considered to be in the public domain? I'm not too familiar with the intricacies of copyright law and intellectual property, so I'm hoping you can provide some insight. Is Minnie Mouse's image and character free to use by anyone, or does she still belong to a specific company or entity? Thank you for your time and any information you can provide.