Objectives: Regular walking is a critical target of physical activity (PA) promotion, and dog walking is a feasible PA intervention for a large segment of the population. The purpose of this paper was to review PA interventions that have involved canine interactions and to evaluate their effectiveness. A secondary aim of this review was to highlight the populations, settings, designs and intervention components that have been applied so as to inform future research. Design: Systematic review. Data sources: We carried out literature searches to August 2019 using six common databases. Eligibility criteria: Studies included published papers in peer-reviewed journals and grey literature (theses and dissertations) in the English language that included any PA behaviour change design (ie, randomised controlled trial, quasi-experimental) that focused on canine-related intervention. We grouped findings by population, setting, medium, research design and quality, theory and behaviour change techniques applied. Results: The initial search yielded 25 010 publications which were reduced to 13 independent studies of medium and high risks of bias after screening for eligibility criteria. The approaches to intervene on PA were varied and included loaner dogs, new dog owners and the promotion of walking among established dog owners. Findings were consistent in showing that canine-assisted interventions do increase PA (82% of the studies had changes favouring the canine-facilitated intervention). Exploratory subanalyses showed that specific study characteristics and methods may have moderated the effects. Compared with studies with longer follow-up periods, studies with shorter follow-up favoured behaviour changes of the canine intervention over the control condition. Conclusion: Canine-based PA interventions appear effective, but future research should move beyond feasibility and proof of concept studies to increase rigour, quality and generalisability of findings.