A check valve for a combustion engine fuel system includes a polymeric poppet valve including a valve stem and a valve head that terminates the valve stem. A valve seat is adapted for cooperation with the valve head of the poppet valve, and includes a valve seat body and an elastomeric valve seat seal supported by the valve seat body and adapted for sealing against the valve head of the poppet valve. The check valve is particularly adapted for use with a fuel pump within a fuel system.