The Schools celebrated its 150th jubilee during October 2005 and has a proud tradition of producing Springboks with Ollie le Roux, Ruan Pienaar, CJ van der Linde, Bismarck du Plessis and Francois Steyn amongst it's former pupils.
The Blues are due to fly out on the 27th of July and play a match against Toyota Free State Cheetahs on Saturday 4 August.
Speaking of the announcement, newly appointed Cardiff Blues Director of Rugby, Phil Davies, said:
"This is a fantastic opportunity for us to put a stake in the ground in a major rugby country and a great opportunity for youngsters to be tested in a high pressure environment."
"South Africans are passionate about their rugby and we feel very honoured that they have invited Cardiff Blues over to play a match."
Cardiff Blues CEO Richard Holland added,
"On behalf of Cardiff Blues I would like to thank Grey College and Toyota Free State Cheetahs for extending this invitation to us."
"We are naturally delighted that such a prestigious establishment, with such a proud rugby history, has invited Cardiff Blues to play."
"It is a reflection of the standing and the international recognition of the Cardiff Blues brand that they have chosen us."
"I would also like to thank the WRU, SARU and the IRB for their assistance in sanctioning this match."