Background:The primary purpose of this review is to synthesise the effect of strategies aiming to sustain the implementation of evidenced based interventions (EBIs) targeting key health behaviours associated with chronic disease (i.e., physical inactivity, poor diet, harmful alcohol use and tobacco smoking) in clinical and community settings. The field of implementation science is bereft of an evidence base of effective sustainment strategies, and as such this review will provide important evidence to advance the field of sustainability research.Methods:This systematic review protocol is reported in accordance with the Preferred Reporting Items for Systematic review and Meta-Analysis Protocol (PRISMA-P) checklist (Additional file 1). Methods will follow Cochrane gold-standard review methodology. The search will be undertaken across multiple databases, adapting filters previously developed by the research team; data screening and extraction will be performed in duplicate; strategies will be coded using an adapted sustainability-explicit taxonomy; evidence will be synthesised using appropriate methods (i.e. meta-analytic following Cochrane or non-meta-analytic following SWiM guidelines). We will include any randomised controlled study that targets any staff or volunteers delivering interventions in clinical or community settings. Studies which report on any objective or subjective measure of the sustainment of a health prevention policy, practice, or program within any of the eligible settings will be included. Article screening, data extraction, risk of bias and quality assessment will be performed independently by two review authors. Risk of bias will be assessed using Version 2 of the Cochrane risk-of-bias tool for randomised trials (RoB 2). A random effect meta-analysis will be conducted to estimate the pooled effect of sustainment strategies separately by setting (i.e. clinical and community). Sub-group analyses will be undertaken to explore possible causes of statistical heterogeneity and may include: time period, single or multi strategy, type of setting and type of intervention. Differences between sub-groups will be statistically compared.Discussion/Conclusion:This will be the first systematic review to determine the effect of strategies designed to support sustainment on sustaining the implementation of EBIs in clinical and community settings. The findings of this review will directly inform the design of future sustainability-focused implementation trials. Further, these findings will inform the development of a sustainability practice guide for public health practitioners.Registration:This review was prospectively registered with PROSPERO (registration ID: CRD42022352333)