Externalising behaviour in childhood is a prevalent problem in the field of child and adolescent mental health. Parenting interventions are widely accepted as efficacious treatment options for reducing externalising behaviour, yet practical and psychological barriers limit their accessibility. This review aims to establish the evidence base of self-directed (SD) parenting interventions for externalising behaviour problems. Electronic searches of PubMed, Web of Knowledge, Psychinfo, Embase and CENTRAL databases and manual searches of reference lists of relevant reviews identified randomised controlled trials and cluster randomised controlled trials examining the efficacy of SD interventions compared to no-treatment or active control groups. A random-effect meta-analysis estimated pooled standard mean difference (SMD) for SD interventions on measures of externalising child behaviour. Secondary analyses examined their effect on measures of parenting behaviour, parental stress and mood and parenting efficacy. Eleven eligible trials were included in the analyses. SD interventions had a large effect on parent report of externalising child behaviour (SMD = 1.01, 95 % CI: 0.77–1.24); although this effect was not upheld by analyses of observed child behaviour. Secondary analyses revealed effects of small to moderate magnitude on measures of parenting behaviour, parental mood and stress and parenting efficacy. An analysis comparing SD interventions with therapist-led parenting interventions revealed no significant difference on parent-reported measures of externalising child behaviour. SD interventions are associated with improvements in parental perception of externalising child behaviour and parental behaviour and well-being. Future research should further investigate the relative efficacy and cost-effectiveness of SD interventions compared to therapist-led interventions.