Abstract Background Meeting the 24-hour movement behavior (24-HMB) guideline helps enhance quality of life (QOL) of adolescents. This study aimed to assess the associations between the 24-HMB (physical activity, screen time, sleep) and QOL among adolescents with idiopathic scoliosis. Methods A cross-sectional study was conducted between September 2021 and September 2023. 24-HMB, QOL and demographic variables were collected through a self-reported questionnaire. Linear regression models and stratified analyses were used to explore statistical associations between the 24-HMB and QOL. Results A total of 1073 participants aged 10–18 years with a spinal Cobb angle between 10° and 40° were included. Overall, 20 participants (1.9%) met all three behavioral guidelines, and 272 participants (25.3%) met none. Compared to those who did not meet any of the guidelines, adolescents meeting both screen time and sleep duration (β = 4.10, 95% CI: 2.02–6.18, P