Can I represent myself in Pennsylvania courts?

Yes you can, if you are a natural person, i.e. a human being, you can represent yourself. This is called “pro se” representation. However, in most cases, you cannot represent a company with which you are associated. An exception to this is representation of companies in proceedings in Magisterial District Courts where a shareholder or officer or partner may represent a company. Also, an employee of the company or authorized agent who has personal knowledge of the facts of the case may represent the company if authorized in writing by an officer or partner of the company.