Background Insufficient physical activity (PA) is a significant risk factor that contributes to obesity and there is a need to improve understanding about how to increase PA, particularly among young children. This review (PROSPERO registration: CRD42022328841) investigated the relationship between Behaviour Change Techniques (BCTs) and interventions that increased PA among young children (< 6 years old, pre-school).Methods Systematic searches of six databases were undertaken from inception to July 2022, updated in December 2022, to locate trials that evaluated interventions and reported a positive change in PA levels in children aged < 6 years old.Results A total of 5,304 studies were screened and 28 trials involving 10,605 subjects aged from 2.5 to 5.9 years old met eligibility criteria. Each eligible study (n = 28) was independently appraised by two researchers using the Cochrane risk of bias tool. The BCT Taxonomy v1 and the Template for Intervention Description and Replication (TIDieR) guided the extraction and analysis of data and this process led to the identification of 27 BCTs.Conclusions Potentially promising BCTs for increasing PA among young children included ‘shaping knowledge,’ ‘antecedents,’ ‘goals and planning,’ and ‘comparison of behaviour.’ Future PA interventions that target young children should consider integrating these promising BCTs into their programmes. However, such consideration needs to be tempered with the fact that most reviewed studies were deemed to have a high or unclear risk of bias and/or were limited with respect to the populations they targeted. There is a need for further methodologically rigorous intervention research that prioritises at-risk child populations with low PA levels, particularly children from disadvantaged socioeconomic communities.