Objectives Dental caries is the most common preventable childhood condition. Non-dental professionals and health workers are often well placed to support parents in adopting positive oral health behaviours for their children. The aim of this study was to determine the effectiveness of behaviour change interventions and their individual component behaviour change techniques (BCTs), that were delivered by non-dental professionals and health workers. Methods A systematic search of Ovid MEDLINE, PubMed, CINAHL, Cochrane Library, Web of Science, TRoPHI and PROQUEST from inception until March 2021 was conducted. Randomised controlled trials and quasi-experimental studies for improving oral health outcomes in children were included. Quality assessment was carried out using Cochrane Risk of Bias tool and ROBINS-I tool. Publication bias was assessed using funnel plots and Egger’s regression intercept. Effect sizes were estimated as standardised mean difference (SMD) and odds ratio/risk ratio for proportions. Meta-analyses were performed for studies reporting mean decayed, missing, filled surfaces (dmfs) and mean decayed, missing, filled, teeth (dmft) indices. Behaviour change technique coding was performed using behaviour change technique taxonomy v1 (BCTTv1). Results Out of the 9,101 records retrieved, 36 studies were included with 28 showing a significant effect either in clinical and/or behavioural/knowledge outcomes. Most studies (n = 21) were of poor methodological quality. The pooled SMD for caries experience showed statistically significant result for caries prevention at surface level -0.15 (95% CI -0.25, -0.04) and at the tooth level -0.24 (95% CI -0.42, -0.07). In 28 effective interventions, 27 individual BCTs were identified and the most frequently used were: “Instructions on how to perform the behaviour” and “Information about health consequences”. Conclusion There is low quality of evidence suggesting non-dental professionals and health workers may help improve oral health outcomes for children. To confirm these findings, further high-quality studies incorporating a variety of BCTs in their interventions for adoption of good oral health behaviours are needed.