Introduction Oral diseases and conditions affect the physical, social, and psychological well-being of an individual. The aim of this study was to determine the association between the severity of dental fluorosis and oral health related quality of life (OHRQoL) among 15-year-old school children residing in an endemic area for dental fluorosis in Sri Lanka. Design A cross-sectional study was conducted among 989, 15-year-old school children who were lifetime residents of Kurunegala district. A validated Sinhala version of the Child Perception Questionnaire (CPQ 11–14) was used to assess OHRQoL. Dental fluorosis was assessed using the Thylstrup and Ferjeskov index (TF index) while dental caries and malocclusion were assessed using the WHO Basic Methods and Dental Aesthetics Index (DAI) respectively. In addition, information pertaining to parental level of education, type of toothpaste used, frequency of toothbrushing and use of dental services was also gathered. Results The prevalence of dental fluorosis was 52%. The overall prevalence of impacts based on the CPQ was 38.2%. The severity of dental fluorosis was not significantly associated with the overall prevalence of impacts. However, the severity of dental fluorosis was significantly associated with three oral impacts namely “having pain in teeth, lips, jaws, or mouth”, “felt irritable or frustrated” and “other children teased or called names”. According to the multiple logistic regression analysis, use of dental services and moderate to severe malocclusion were significantly associated with poor OHRQoL but not dental fluorosis. Conclusion The severity of dental fluorosis was not associated with OHRQoL of the participants.