Are you employed in the U.S.? Do you work in the private sector? Are you a non-unionized worker? If you answered yes to all of these questions you’re most likely covered by at-will employment. Being an at-will employee means that you can be fired at any time for any reason or no reason at all. It’s perfectly legal and if it happens, you have no power to get justice. Of course there are covered identity groups and reasons that are illegal to fire someone for, like race or ethnicity. But otherwise, your employer doesn’t need a reason to fire you.
This just changed in New York City! In January, a law was passed in NYC requiring just cause, or a good reason, for firing someone. You can still be fired for not doing your job well but not for having your hair dyed a color your employer doesn’t like. This law is a huge milestone and proves that we are one step closer to passing the PRO Act.