Abstract Background Digital health literacy (DHL) involves the ability to find, understand, appraise, and apply health information from digital sources. It serves as the foundation for informed decision-making about one’s health and well-being using digital technology and online health information sources and services. Despite its significance, the role of DHL in relation to schoolchildren’s wellbeing remains underexplored. Therefore, this study aims to investigate how schoolchildren’s DHL influences their physical, mental, and academic well-being. Methods The cross-sectional survey comprised a representative sample of N = 1448 school-aged children (9-18 years) living in Germany. DHL was assessed via a translated and adapted version of the DHL instrument. The assessment of physical, mental, and academic well-being relied on the KINDL questionnaire. Linear regression analyses were conducted, with the scale score of physical, mental, and academic well-being serving as dependent variables and DHL as predictor. Additionally, potential confounding variables such as sex, age, migration background, subjective family wealth, chronic illness, and subjective health status were included in the analyses. Results All three regression models were significant (physical: F(9,1325) = 34.99, p < .001; R2 = 0.19; mental: F(9,1320) = 27.43, p < .001; R2 = 0.16; academic: F(9,1336) = 15.19, p < .001; R2 = 0.09). DHL significantly predicted physical (B=.08, p=.01), mental (B=.17, p<.001), and academic (B=.21, p<.001) wellbeing. Conclusions This study provides the first evidence of the predictive power of DHL for schoolchildren’s physical, mental, and academic well-being. It emphasizes the importance of promoting DHL in schoolchildren to empower them to find, understand, appraise, and apply digital health information effectively. Key messages • Digital health literacy significantly predicts schoolchildren’s physical, mental, and academic well-being. • Promoting digital health literacy can empower schoolchildren to make informed decisions about their well-being.