The new tournament, launched last year, brings together some of the biggest names in club and provincial rugby from the Northern and Southern Hemispheres, with some of the emerging names in the Sevens game.
The tournament is set to expand further in 2015 as Sevens 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 Sevens.
Rugby Director at Premiership Rugby, Phil Winstanley, said: "The World Club Sevens goes from strength to strength and it is great to see these four Sevens powerhouses confirmed already.
"We will be confirming the other eight sides in due course. 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 Sevens 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 even better."
Special discounted ticket offers are available for a limited period only here or by calling 0844 847 2492. Daily prices are from £10 for adults and kids (Under 16) and weekend tickets for as little as £15 (booking fees apply).