Based on the latest publicly available data and standard demographic-projection logic, the Sinhalese are the ethnic group most likely to remain the largest in Sri Lanka by the year 2300.
Current baseline
• Sinhalese already form roughly three-quarters of the population (about 75 %) [Sinhalese people](https://en.wikipedia.org/wiki/Sinhalese_people)[Sri Lanka](https://en.wikipedia.org/wiki/Sri_Lanka).
• Sri Lankan Tamils and Moors follow at around 11 % and 9 % respectively [Sri Lanka](https://en.wikipedia.org/wiki/Sri_Lanka)[Sri Lankans Are Positive About Religious Diversity, Says ...](https://thediplomat.com/2023/09/sri-lankans-are-positive-about-religious-diversity-says-pew-survey/).
Why the Sinhalese share is expected to hold or rise
1. Higher total fertility rate (TFR)
– Recent national surveys show the Sinhalese TFR sits noticeably above that of Tamils or Moors, so each generation replaces itself at a slightly faster pace.
2. Majority‐population momentum
– Because 3 out of 4 citizens are Sinhalese, even identical fertility rates would keep them numerically dominant for centuries; a modestly higher rate amplifies that lead.
3. Lower emigration pressure
– Historical migration data indicate Tamil and Moor communities have had higher relative out-migration due to economic opportunity or past conflict, whereas Sinhalese net outflows are smaller, preserving their domestic share.
4. Cultural and linguistic assimilation
– Mixed marriages and urban migration tend to shift smaller-group members toward Sinhala language use and Buddhist cultural practices, gradually swelling the Sinhalese-identified population.
Model caveats
• Projections assume no transformative shocks—e.g., major civil conflict, mass immigration, or differential impacts of climate change.
• Sri Lanka’s overall fertility is trending downward; if the Sinhalese TFR eventually converges with or drops below minority rates, the gap could narrow.
• Policy choices on regional autonomy, diaspora return programs, or economic incentives could alter migration balances.
Bottom line
Given their current 75 % share and slightly higher fertility, the Sinhalese population is set to remain, and very likely increase as, the largest ethnic group through 2300 under any projection that simply extends today’s trends without extraordinary disruptions [Sri Lanka](https://en.wikipedia.org/wiki/Sri_Lanka)[Sri Lanka Population 2025](https://worldpopulationreview.com/countries/sri-lanka).