The four teams representing each of the countries in the Rugby Championship ensure a powerful southern hemisphere presence in the tournament at Twickenham Stadium on 16 & 17 August.
The new tournament - launched last year - brings together, some of the biggest names in club and provincial rugby from the Northern and Southern Hemispheres together, with some of the emerging names in the 7s game.
The tournament is set to expand further in 2015 as 7s Rugby heads towards its debut at the Rio Olympics in 2016 and will include the strongest club and provincial teams in the world.
The cross-hemisphere tournament will be fought out between 12 sides from across the globe, including the winner of this summer's Premiership Rugby 7s.
"The World Club 7s goes from strength to strength and it is great to see these four 7s powerhouses confirmed already," said Phil Winstanley the Rugby Director at Premiership Rugby.
"We will be confirming the other eight sides in due course - as we have had a lot of interest from around the world since last year's event - but we can guarantee they will create a feast of 7s action at one of the most iconic stadiums in the world.
"The first event proved to be a fantastic weekend for all the family and this time around it will be ever better."
Special discounted ticket offer are available for a limited period only, click here or call 0844 847 2492. Daily from £10 for adults & kids (U16) and weekend tickets for as little as £15 (booking fees apply).