The details of it are that a friend of the baby daddy is falsely claiming to be the father of my child. He was over my house 24/7 cause he's friends with my brother. He got on my nerves, I cussed him out, and then he went to my exboyfriend and told him that he didn't like me. The boyfriend broke up with me because of that and then he spread around that he was the father of my child. I would like to know if I can sue him for slander/defamation/harassment.

Try asking him for child support and see how fast he recants his story. Honesty if he went to court and said he believed he was the father then you really would have no grounds to stand on. Is there a current legal father for the child? Is there someone else on the birth certificate or that has been through the courts for a DNA test?

If not then you need to do that and get child support for the child. You will kill 2 birds with one stone.

Its not really slander or defamation. You obviously had a child. It could be harassment though, but you would have to prove you were damaged.

If you boyfriend broke up with you because someone else was claiming to be the father, then why not have offered your boyfriend to have a paternity test done? If he broke up with you over this, he was probably just looking for an excuse.

But Califdad is right, file a claim for child support.