AimTo evaluate the acceptability, feasibility and potential effectiveness of a group‐based instrumental musical training programme in improving resilience, depressive symptoms, self‐esteem and quality of life among school‐aged children from low‐income families.DesignAssessor‐blinded pilot randomised waitlist controlled trial with process evaluation.MethodsThis study was conducted in the community from January 2022 to July 2023. Sixty‐four children from low‐income families (aged 8–12 years) were randomised (1:1) to intervention and waitlist control groups. The intervention group (n = 32) received weekly 1‐hour instrumental musical training for 6 months in groups of four to five from professionally qualified musicians at a music centre. The participants in the waitlist control group (n = 32) received the same intervention as the participants in the intervention group after the completion of all outcome assessments. The primary outcome was the children's levels of resilience, measured using the Resilience Scale for Children – 10. The secondary outcomes were depressive symptoms, self‐esteem and quality of life. Assessments were conducted at baseline (T0) and immediately post‐intervention (T1). An intention‐to‐treat analysis was performed.ResultsThe 64 participants had a mean (SD) age of 9.5 (1.44) years, and 37 (57.8%) were boys. Compared with the waitlist control group, participants in the intervention group showed significantly greater improvements in resilience levels from baseline to T0 (group‐by‐time interaction coefficient β = 4.41; 95% CI, 1.82–6.99; p = 0.001), depressive symptoms (β = −6.42; 95% CI, −11.12 to −1.71; p = 0.008), self‐esteem (β = −2.60; 95% CI, 0.28–4.92; p = 0.028) and quality of life (β = 6.69; 95% CI, 0.18–13.2; p = 0.044).ConclusionThe group‐based instrumental musical training programme was feasible and acceptable for school‐aged underprivileged children and showed the potential to improve the resilience and quality of life of this vulnerable population.