Abstract: A portable door lock comprises a jam plate connected through a hinge to a latch plate through a hinge that allows the latch plate to swing from a lock position alongside a door to an unlock position alongside a door jam when the portable door lock is installed in a door jam recess between a door and a door jam so the lock can remain installed yet allow the door to be opened for normal use or locked. A jam plate tongue extends orthogonally from the jam plate adjacent a jam plate hole sized to receive a door latch striker therethrough. Preferably two opposing upper and lower hooks opening in opposite directions swivel on the latch plate on a pivot pin in a plane parallel to the latch plate one hook applicable for a right-hinged door, the other for a left-hinged door. The hooks also may wrap and hook a doorknob shank from above and below.