European Rugby has confirmed the addition of five leading South African teams to the Champions Cup and the Challenge Cup from next season.
The Stormers, Bulls, Sharks, and Lions have qualified for the top-tier competition through their performances in the United Rugby Championship.
While the Cheetahs will be taking part in the Challenge Cup.
The formats of the competition and the pool draws will be announced towards the end of the month.
The finals weekend for next season will see Dublin's Aviva Stadium hosting on the third week of May.
Commenting on the major development, EPCR Chairman, Dominic McKay, said: "We are delighted to confirm that the South African clubs will be part of our expanded tournaments from the beginning of next season.
"The Stormers, Bulls, Sharks and Lions will all bring hugely exciting southern hemisphere rugby, well-known world-class players and broad new audiences into our tournaments, and we are pleased to welcome the Cheetahs into the EPCR Challenge Cup. The steps we have taken with our stakeholder leagues and with SARU ensure that we can further develop the tournaments as the pinnacle of global club rugby. "This is a crucial step forward in bringing to life our vision of growing the game and our own tournaments, continuing to deliver strong returns for our leagues and creating an ever-higher standard of mouthwatering matches for our fans."