The invention is directed to pyridazinone compounds of Formula I and pharmaceutical compositions containing compounds of Formula I ##STR00001## wherein R.sup.1 and R.sup.2 are independently H, alkyl, cycloalkyl, aryl, or heterocyclyl; and Ring A is 5 or 6-membered aryl or heterocyclyl. The invention also encompasses methods of using a compound of Formula I in the treatment of hepatitis C virus infections.