Introduction: Non-adherence to inhaled corticosteroids (ICS) in children with asthma leads to significant morbidity and mortality. Few interventions to improve adherence have been effective and little is known about what contributes to intervention effectiveness. This systematic review summarises the efficacy of these interventions and the characteristics of effective interventions to inform future studies aiming to improve adherence to ICS in children with asthma. Methods: PubMed, Embase, PsychINFO, Medline, Web of Science, and International Pharmaceutical Abstracts were systematically searched on the 3rd of October 2020 for randomised control trials measuring adherence to ICS in children with asthma. A narrative synthesis was conducted focusing on intervention efficacy and study reliability. Intervention content was coded based on the NICE guidelines for medicines adherence (The Perceptions and Practicalities Approach, PAPA) and Behaviour Change Techniques (BCT), to determine the effective aspects of the intervention. Results: Of 240 studies identified, 25 were eligible for inclusion. Thirteen of the twenty-five studies were categorised as being highly reliable. Nine of the thirteen studies were effective at increasing adherence and six of those met the criteria for a PAPA intervention. Conclusion: Adherence interventions in children with asthma have mixed effectiveness. Effective studies tended to be of higher quality, were tailored to individuals perceptual and practical adherence barriers, and used multiple BCTs. However, due to the small number of included studies and varying study design quality, conclusions drawn here are preliminary. Future research is needed to test a PAPA-based intervention with a rigorous study design as outlined in this review