The World XV will play a South African XV at Ellis Park on 3 June and a Corne Krige XV at Newlands six days later.
The latter match is to honour the former Springboks and Stormers skipper.
Former Australia World Cup-winning coach Bob Dwyer, who now looks after the Barbarians, will coach the team, and be assisted by former Wales coach Mike Ruddock.
Many of the squad also features in the Barbarians side to play England at Twickenham on Sunday, 28 May.
"We are fortunate that many great players have made themselves available," said Dwyer.
World XV Squad
Backs: Matt Burke (Australia), Isa Nacewa (Auckland Blues), Bruce Reihana (New Zealand), Joe Roff (Australia), Thomas Castaignede (France), Fraser Waters (England), Cedric Debrosse (France), Carlos Spencer (New Zealand), David Humphreys (Ireland), Justin Marshall (New Zealand), Mark Robinson (New Zealand).
Forwards: Mark Regan (England), Raphael Ibanez (France), Christian Califano (France), Dave Hewett (New Zealand), Andrea Lo Cicero (Italy), Cobus Visagie (South Africa), Peter Bracken (Wasps), Tom Palmer (England), Owen Finegan (Australia), Olivier Magne (France), Sam Harding (Northampton), Xavier Rush (New Zealand), Toutai Kefu (Australia), Sebastian Chabal (France), Julien Pierre (Bourgoin).