Purpose: Theory remains underused in social marketing despite many potential benefits that may arise if theory is concretely and consistently applied. In response to ongoing calls for standardised frameworks and methods, this study aims to present a four-step theory application process with the aim of supporting improved theory use across the entire social marketing process. Design/methodology/approach: The role and importance of theory application in behaviour change is outlined alongside an integrative review and critical analysis of theory application in social marketing. To address key challenges impeding rigorous theory use, the theory selection, iterative schematisation, theory testing and explicit reporting of theory use (TITE) four-step theory application process is proposed. Evidence-based guidance, current best practice examples, and a worked example are provided to illustrate how the TITE process may be initially followed. Findings: Low levels and poor quality of theory use suggest social marketing researchers and practitioners need further support in rigorously applying theories across the life of an intervention. The TITE process leverages the known benefits of theory use and capitalises on the reciprocal relationship that may be enacted between theory selection, iterative schematisation, theory testing and explicit reporting of theory use. Research limitations/implications: The TITE process delivers a standardised framework that aims to stimulate rigorous theory application and explicit reporting of theory use in social marketing. Clear theory application and reporting will permit a more fine-grained understanding of intervention effectiveness to be established by shifting away from a simple dichotomous view of effectiveness (success or failure) to unpacking the “active ingredients” contributing to observed outcomes. Practical implications: The evidence-based guidance and best practice examples provided for each step of the TITE process will increase the accessibility and usability of theory among practitioners. With time the TITE process will support practitioners by delivering a robust theory base that can be reliably followed to further extend on social marketing’s effectiveness. Originality/value: This paper draws on interdisciplinary methods and resources to propose a standardised framework – the TITE process – designed to support rigorous theory application and explicit reporting of theory use in social marketing. Refinement, uptake and widespread implementation of the TITE process will improve theory use and support the creation of a shared language, thereby advancing social marketing’s cumulative knowledge base over time.