Ireland avoided all the Southern Hemisphere teams as they were drawn alongside France and Italy in Group D, and will strongly fancy their chances of progressing to at least the quarter-finals following the draw made at Tate Modern in London.
Stuart Lancaster's England side face a huge challenge to get out of Group A .
2011 semi-finalists Wales dropped into the third group of seeds after a disastrous autumn international campaign and face rivals England along with double World Cup winners Australia.
Scotland, who were also in the third group of seeds, face a somewhat easier task after being drawn with South Africa and Samoa.
Only 12 of the 20 teams are known, with the other eight coming from a qualifying competition.
The World Cup takes place from September 18 to October 31, 2015, with the final at Twickenham.
The top two teams in each group will qualify for the knock-out stages, while the top three qualify automatically for the 2019 tournament in Japan.