Hollywood star Michael Sheen, Marvin Humes and Aston Merrygold from JLS, Gordon Ramsay, DJ Jamie Theakston and footballers Teddy Sheringham and Edwin van der Sar are the first stars to sign up to join Williams's project.
The 2010 series of Soccer Aid ended with a victory for Michael Sheen's Rest of the World team over Robbie Williams's England, following a nail-biting penalty shoot-out, which concluded with Woody Harrelson scoring the winning spot kick.
It was the first time that the Rest of the World team had managed to triumph over England at Soccer Aid.
Watch the finale of the 2010 Soccer Aid penalty shoot-out below:
Returning for a fourth series, the latest re-match will take place at Manchester United's Old Trafford ground and will be hosted by Dermot O'Leary. Dave Berry will front the Extra Time coverage on ITV4.
O'Leary will also host three build-up shows from the players' hotel, which will feature behind-the-scenes footage and direct access to the stars taking part.
UNICEF UK ambassador Williams said: "Soccer Aid returns for the fourth time and with it a renewed sense of passion for this remarkable event that can help vulnerable children all around the world. I make no bones about it, we lost, the Rest of The World managed to scrape together a jammy victory.
"Soccer Aid this year will be bigger and better than ever because this time it's personal. Michael Sheen, I'm gunning for you son."
Previous Soccer Aid matches have raised over £7 million for UNICEF.
David Bull, UNICEF UK executive director, said: "Soccer Aid 2012 will raise vital money to change children's lives around the world. Every minute of every day, children die from easily preventable diseases like diarrhoea and malaria.
"Right now, children are suffering because they don't have enough to eat. It shouldn't be like this. Please, buy a ticket to go to Soccer Aid or watch the match and help us make a change for children."
Tickets for Soccer Aid 2012 are now on sale. Call 0161 444 2012 and visit ITV.com/socceraid or ManUtd.com/socceraid.