Objectives: To investigate the distribution of groundwater fluoride levels in Sri Lanka in relation to its population distribution to determine the population at risk for dental caries or dental fluorosis. Methods: The study used the most upgraded spatial distribution map of groundwater fluoride levels in Sri Lanka, and it was overlaid with a census of population data of the country. Results: The results indicated that 12% of children aged <12 years were at risk for dental fluorosis, while 81.4% of those who lived in low-fluoride zones were vulnerable for development of dental decay. Overall, 82.4% of the country's population lived in low-fluoride zones and 11.2% were at risk of potential health hazards posed by ingestion of excessive fluoride. Conclusion: The spatial approach provides a useful decision-support tool for developing an oral health strategy of safe fluoride use based on predicted oral health risks in communities.