Sri Lanka Cricket last year, appointed Jerome Jayaratne as the interim coach after the resignation of Marvan Atapattu ahead of the West Indies tour of Sri Lanka.
The SLC Chairman said new coach has been contracted to strengthen the national team ahead of the 2016 Asia Cup and World Twenty20 to be held in India from March and he will oversee the national team at the 2019 Cricket World Cup in England.
His appointment ended his two-year stint at Surrey, who had two resurgent seasons under him. They returned to county cricket's top tier, after winning the division two title last year.
"We are extremely disappointed to be losing Graham Ford who has not just been an outstanding head coach but has played an integral role in the progress that we have achieved over the last two years," Surrey's director of cricket Alec Stewart said. "He has worked tirelessly with the players and his efforts can be seen in their individual performances and the team's results, culminating in promotion back to the first division."