Can I file for bankruptcy if I have a judgment against me?

Yes, you may file for bankruptcy relief if you have a judgment against you.  Indeed, that is the final straw that forces many people into bankruptcy.  However, special care should be taken to insure that the discharge will have the desired results.

In many jurisdictions, the entry of a judgment creates a lien upon property held by the debtor at the time of the entry.  This could create a lien upon real estate, which, unless further action is taken, could survive the bankruptcy.  A title search may be necessary to determine whether such a lien has been placed.  In many cases, the lien (judicial) can be avoided in the bankruptcy proceeding by filing the appropriate motion.  The failure to do so. either by a pro se debtor (almost always) or an attorney not fully experienced in bankruptcy practice (too frequently) could result in negative consequences after discharge, sometimes years later.

I would advise you to seek experienced counsel in your area and make sure your attorney is made aware of the judgment.