The newly re-branded club, who will play most of their home games at Twickenham Stoop, will take on Hull at the Priestfield Stadium on Sunday May 20 (2pm kick-off).
“This is an exciting opportunity to take the game to a new audience, meeting our strategic objective of growing the game across London and the South East.
“We very much hope the local community will come out in support of the event and we’re already looking forward to the match.”
The Broncos have already confirmed that they will take a game to Leyton Orient’s ground during 2012.
Gillingham FC Commercial Director Steve Lowe added: “It’s great to be working with the London Broncos to bring another professional sport to Kent, particularly just as the football season will be drawing to a close.
“I hope that the people of Kent come out and support us bringing Super League rugby to the county.
“It should be a great sporting occasion and will showcase Rugby League to all those that follow it on TV, play it and read about it.”