Millions of children and young people (CYP) in low- and middle-income countries (LMICs) have no access to mental health care. This huge treatment gap is primarily due to limited availability of trained mental health professionals. We propose task-sharing as a scalable strategy to expand access to child and adolescent mental health (CAMH) interventions in LMICs. Task-sharing involves using the few mental health specialists in LMICs to train and supervise nonspecialists to provided CAMH interventions. There is strong evidence of clinical and cost effectiveness of task-shared mental health interventions for adults in LMICs and promising evidence for CYP. To succeed, task-shared programmes need to be embedded in a balanced system-wide care setting that includes stakeholder involvement. The existing mental health specialists may require additional training in leadership, supervision, mentoring, service design and evaluation in order to meet the additional expectations of managing task-sharing programmes. The nonspecialists to be trained would need assurances about workload, ongoing supervision, clinical back up for cases that exceed their expertise, certification for their training and career progression. CAMH task-sharing offers good promise for increasing CYP's access to mental health interventions in LMICs. However, planners need to be aware of the important practical, ethical and contextual considerations necessary for success and sustainability.