If a debt collector is suing me, can I settle with them without going to court?

If the the debt collector has already filed a claim in the Court system, then you can come to an agreement which will have to be filed in the Court.  Many times, the debt collector's attorney will handle this without you having to appear in Court.  

If the debt collector has not already filed a claim in the Court system, then you are absolutely able to settle the matter with them without going to Court. 

But be careful of what you sign.  Remember the debt collector is only worried about collecting the money owed.  It is not their job to worry about whether you fully understand anything you are signing.