Can I sue when my criminal conviction was disclosed to management by company employee?
Unfortunately, it is not illegal to disclose another person's criminal conviction, since a criminal conviction is public record. Anyone can disclose anything of public record, so there is no basis to sue.
There's a lot of things we would all like to remain private and that we hope the world forgets. A criminal conviction is certainly one of them, generally ranking even higher on the list of things we would like forgotten than a disastrous relationship with someone all your friends warned you about. However, just because we do not want anyone to disclose a criminal conviction does not mean we can take legal action against--that is, sue--someone who does disclose it.
To hugely oversimplify, there are only three times you can sue someone:
1) when they do something which hurts you that is against a specific law, as for example, an employer failing to pay a nonexempt worker overtime, which violates the Fair Labor Standards Act;
2) when they breach or violate a contract; or
3) when they harm you or cost you money by violating a "common law" duty of care, or a duty to use reasonable care found not in a specific statute but in the law generally. For example, when you sue someone who hit your car while driving carelessly, since the law imposes a duty to drive carefully.
All suits essentially boil down to a violation of a specific law or ordinance, violation of a contract, or violation of some duty of care recognized by the law.
Conversely, that means that if someone did NOT do one of the things discussed above, there are no grounds to sue them, even if you find their actions inappropriate or offensive. In this case, that means that you can't sue a company employee (or anyone) who disclosed your criminal conviction:
(1) there is no statute or other specific law making it illegal to disclose another's criminal convictions. In fact, except for juvenile offenses (in most states; check your state’s specific laws and rules on the subject, if your conviction was a juvenile one) and certain other criminal records specifically sealed by the court, criminal convictions are public records;
(2) the company employee – most likely -- never agreed contractually to not disclose this (i.e., did not sign a non-disclosure agreement with respect to your criminal conviction), so there is no breach of any obligation they agreed to or voluntarily took on; and
(3) there is no generally recognized duty or obligation to not disclose criminal convictions. Unlike, let’s say, the duty to use care when driving, or to not defame someone by uttering untrue factual statements which harm their reputation, the law does not impose on anyone a duty to not disclose information about criminal convictions.
Therefore, there is no possible legal action based on breach of a duty. (Note: if the person lied about your criminal past, that would be different. Lying about it would make it defamation, which you could sue over. However, truthfully disclosing a conviction is not defamation or illegal.)
So as much as you may wish they had not done this, you have no legal grounds to sue. If it's any consolation, management could have discovered this on their own. Employers may run criminal background checks on prospective or current employees, which itself illustrates that looking into or disclosing someone's criminal conviction or background is not illegal.