Wallball is a simple, cheap game that just needs a wall and a ball.
The new facility at the Marlborough Sports Garden is the first step towards London catching up with New York which has more than 2,500 community wallball courts.
"This court is incredibly exciting for us," said Dr Daniel Grant of governing body UK Wallball.
"Any player is going to have a brilliant time playing and with everything we've installed here you don't even need a coach. You can literally teach yourself by watching a video and grabbing a ball from the vending machine.
"Wallball's greatest strength is its simplicity and that is playing out in full here.
"Behind the scenes, by breaking down barriers to getting active, initiatives like this will help to improve both the physical and mental health of anyone who engages, either as players on the court or as artists, BBQ chefs, DJs and volunteers off it."
Gemma Dunbar, head of programme development at the Jack Petchey Foundation said: "We love the way that any young person can turn up, learn a new game with their friends, meet new people, get active, burn off steam, enjoy the outdoors safely and be healthy and have fun. Wallball is a fantastic sport!"
Helena, an eleven year old local girl who attended the opening said: "I got a ball from the machine so I can play with my friends. It's awesome!"
Marlborough Sports Garden is run by Bankside Open Spaces Trust.