St George-Illawarra have completed the line-up for the inaugural World Club Series between Super League and the National Rugby League in February.
The Dragons, 2011 World Club Challenge winners, join NRL premiers South Sydney Rabbitohs and Brisbane Broncos in representing the southern hemisphere.
Souths will play the winners of Saturday's Super League Grand Final between Wigan and St Helens.
Whoever loses joins Warrington to face the Broncos and St George-Illawarra.
Paul McGregor's Dragons have England players Gareth Widdop and Mike Cooper, while Souths could feature three Burgess brothers in Luke, Thomas and George.
England international Jack Reed plays for Brisbane.