Sri Lanka batsman Tillakaratne Dilshan is to join Surrey as their overseas player until the middle of August.
The 37-year-old replaces South Africa's Hashim Amla, who arrived on a short-term deal after captain Graeme Smith suffered a serious knee injury.
Dilshan is expected to make his debut in the T20 Blast against Hampshire on 27 June and will be available to play in all competitions.
However, he will be absent for two weeks in July on international duty.
"It's a fantastic opportunity for me," Dilshan, who has played 87 Tests, 282 one-day internationals and 62 T20 games for his country, told the club website.
"They are one of the most historic clubs in the world and I very much hope to make a big impact whilst there."
Surrey's director of cricket Alec Stewart added: "With the very crowded international fixture list, it's becoming increasingly difficult to sign a high-class overseas cricketer to play in England.
"Therefore, we are very pleased to have been able to secure the services of a player of the calibre of Dilshan."
Dilshan will be appearing in English county cricket for the first time.