The primary law governing nationality regulations is the Ceylon Citizenship Act, which came into force on 15 November 1948.

All persons born in Sri Lanka receive citizenship by descent if at least one parent is a citizen.

[1] Sri Lankan citizenship can be voluntarily relinquished by making a declaration of renunciation.

Sri Lankan citizens who become citizens of another country automatically have their citizenship revoked unless they first obtain government permission allowing them to retain Sri Lankan citizenship.

Dual citizens are prohibited from standing for office in Parliament and are ineligible to become President.