© 2020 Elsevier Ltd Introduction: The study was conducted to examine the effect of the COVID-19 pandemic on health-related quality of life in children. Materials and methods: The study was conducted with 597 children aged 7–13 and their parents using the online data collection tool via social media. Socio-demographic form and Generic Health-related Quality of Life Questionnaire for Children (Kid-KINDL) were used to collect the data. SPSS 23.0 program, descriptive statistics, Mann-Whitney U test and Kruskal-Wallis variance analysis were used to evaluate the data. Results: During the pandemic, 41.5% of the parents stated that their child gained weight, tendency to sleep of 34.2% and tendency to use the Internet of 69.3% increased. The average self-reported quality of life score of the children was found to be 73.91 ± 8.44. The self-esteem sub-dimension score of the children whose tendency to sleep increased during the pandemic (p < 0.05); and the physical well-being (p < 0.001), emotional well-being (p < 0.001), self-esteem (p < 0.001), family (p < 0.01), school (p < 0.05) sub-dimensions and total (p < 0.05) score averages of the children whose tendency to use the Internet were found to be lower. The emotional well-being, family and friends sub-dimensions as well as total average scores of the children of the parents who feel fear/anxiety about coronavirus becoming a pandemic and who stated that lockdown negatively affected their mental health were found to be lower (p < 0.05). Conclusion: Although self-reported quality of life scores of children were generally good, parents reported that their children gained weight, tendency to sleep and internet use increased during the pandemic.