Sri Lankan presidential line of succession
The Sri Lankan presidential line of succession is the order in which the Prime Minister of Sri Lanka and other persons of the Sri Lankan government may assume the powers and duties of the President of Sri Lanka upon the incapacity, resignation or death of an incumbent President. Constitutional procedure
The first of three paragraphs that make up Article 40 of the Constitution states that:

Current order 
Until the Parliament of Sri Lanka is able to elect a new president, the following order is applied for the line of succession to act as President of Sri Lanka. The current presidential line of succession as specified by the constitution is:

List of acting presidents

References

Government of Sri Lanka