The left-arm seamer agrees to a white-ball deal but could also feature in the Championship on a game-by-game basis
Surrey have made Reece Topley their latest signing ahead of the 2020 campaign.
The 25-year-old turned down a new contract at Sussex in order to move to The Oval. He took 17 wickets in 11 T20 Blast outings for the Sharks last term as they reached the quarter-finals.
Topley, who has represented England in 10 one-day internationals and six T20Is, spent three months of last term at Hove while recovering from back surgery.
He has agreed a two-year white-ball deal at The Oval but is available for Championship games on a match-by-match basis.
“I am honoured to sign a contract at Surrey, and excited to play in front of the fans at the Kia Oval," the left-armer said.
"The set-up here is renowned for being excellent and I can’t wait to work with the players and coaches and aim to win some silverware.“
Director of cricket Alec Stewart added: “Being able to add an international bowler of Reece’s ability is a massive boost to the squad and we look forward to seeing all his skills on view next season and beyond.”
Confirmation of Topley's move comes amid a flurry of new arrivals in south London. Aussie seamer Michael Neser has joined for the first half of the Championship season, while Shadab Khan and D'Arcy Short have signed up as overseas players for the Blast.