Varndell has been out of favour at Leicester this season
Wasps have announced a trio of signings for the 2009-10 season after agreeing two-year contracts with Steve Kefu, Dan Ward-Smith and Tom Varndell.
Australian centre Kefu, 29, arrives from Castres Olympique, number eight Ward-Smith, 31, from Bristol and 23-year-old wing Varndell from Leicester.
"These signings show our intent to be challenging for honours next season," said head coach Shaun Edwards.
Wasps currently lie ninth in the Guinness Premiership.
James Haskell, Riki Flutey and Tom Palmer will all leave Wasps to ply their trade in France next season, while Tom Voyce recently revealed he will depart for Gloucester at the end of the season.
Varndell, who has four England caps, would appear a ready-made replacement for Voyce.
He said: "I am very pleased to be joining London Wasps, a club whose history and achievements speak for themselves.
"Having played for a club like Leicester, the move to Wasps offers me a new challenge in a new environment.
"There is a really good feeling at the club despite a pretty tough season. I have been very impressed with what I've seen and heard. I am just really looking forward to being a part of it."
Kefu, who won six caps for Australia between 2001-2003, added: "To join such a prestigious club and play rugby in the most competitive competition in the northern hemisphere will be a huge challenge and a huge opportunity for me."
And Ward-Smith immediately looked to earning a recall to the England squad, having not featured since his call-up to the training squad ahead of the 2007 World Cup.
"I still have great ambitions to play for England and Wasps have a proven track record of producing and developing players to their full potential and I am really looking forward to becoming a better player, whilst helping to strengthen such a great club," he said.
Director of rugby Ian McGeechan said he was delighted to have made the signings.
"Dan Ward-Smith one of the strongest back row carriers in the Guinness Premiership, Tom Varndell is probably one of the most promising young wingers in the game and Steve Kefu provides us with the experience we want to replace Riki Flutey at 12."