Jayawardene, named Captain of the Year at the recent International Cricket Council awards ceremony, was appointed as a caretaker captain in February after an injury to Marvan Atapattu.
But Jayawardene's outstanding leadership, coupled with Atapattu's decision to opt-out of the forthcoming Test series in New Zealand, persuaded the selectors to give him the job on a full-time basis.
"Mahela has done a good job since taking over from Marvan Atapattu and he will continue till the World Cup," Sri Lanka's chairman of selectors Ashantha de Mel told reporters on Monday.
"We are working towards the World Cup and we wanted to ensure that Mahela felt comfortable ahead of the tournament," de Mel added.
Jayawardene thrived as a batsman under the increased responsibility of the captaincy, averaging 62 in Test cricket and 46 in one-day cricket.
He also hit Test cricket's fourth highest score of 374 during a recent 2-0 win against South Africa.
