Can I do anything about untrue statements that my former employer made about me to a potential employer?

If there are untrue statements made by the former employer, the question is, were these defamatory statements? If they’re defamatory or they cast the employee in a false light, then there can be a claim for defamation. There also might be a claim for retaliation. That’s why it’s typically advisable for employers to be very careful about what they say about an employee to others after the employment relationship had ended.