Director General of Health Services issued a special circular announcing the revised quarantine measures for travelers arriving in the country from overseas. Those arriving in Sri Lanka from overseas after 14 days of full vaccination no longer need to undergo 14 days quarantine IF their on-arrival PCR is tested NEGATIVE. This is NOT applicable to travel restricted countries.
The new quarantine measures specified in the guidelines will apply to Sri Lankans including Sri Lankan seafarers, Dual Citizens as well as foreign nationals. More details here via Health Ministry website.