Legal Question in Civil Litigation in California

Only if that indvidual is an attorney.

Mr. Selik is right, only if they are a licensed attorney in California.

Mr. Selik and Mr. Roach are basically correct, but I want to add that non-attorneys can represent corporations in small claims cases. Small claims cases are heard by specialized divisions of the superior courts, so in those cases the answer to your question would be yes. (We often refer to small claims courts as if they were separate entities, but they actually are not -- at least in California.)

Even in small claims cases, the person who represents a corporation must be an officer or employee. The representative may, but need not, be a lawyer. But companies may not give lawyers token positions in order to create a basis to send them to small claims court.