Kumar Sangakkara, the world's No. 1 Test batsman, has agreed a two-year deal with Surrey although how much he plays in 2015 will not be confirmed until Sangakkara makes a decision over his Test future.
Sangakkara will end his ODI career after the World Cup and he has previously hinted strongly that it will mark the conclusion of his international days, although there remains a chance of a final spell in Test cricket later this year.
His arrival at Surrey will see him back working with Graham Ford, the former Sri Lanka coach, who is now in charge at The Oval.
"We're delighted that Kumar has agreed to join us. He is the number one Test batsman in the world but it's the special character that he has which is as important to us," Alec Stewart, the Surrey director of cricket, said.
"He is a five-star player and five-star person and that is important because he will be working with our young homegrown players as they become serious cricketers at this level. He has worked a lot with our coach Graham Ford, when he was in charge of Sri Lanka, and we are both very happy to reach this stage."
Sangakkara enjoyed a prolific 2014, setting a new record for the most international runs scored in a year with 2868 runs across all formats. He has started 2015 in similar manner, too, with a double hundred against New Zealand in Wellington.
A signing of a player of Sangakkara's standing will also cast further doubt over Kevin Pietersen's future at The Oval as there are salary cap restrictions in place for county squads.