Background <p>Research and theory in the field of implementation science (IS) are increasingly prioritizing health equity. Although this shift is an important development for the field, IS has not yet systematically engaged with theories and methods of critical social science that help to clarify the challenges and opportunities of efforts to improve health equity. In our paper, we present a summary of recent contributions to dialogue on health equity in the field of IS and highlight the value of critical social science theory to advance research and action for social justice and equity in implementation research and practice.</p> Methods <p>We conducted a targeted literature review using citation tracking on Google Scholar. We purposefully selected 10 articles and inductively identified three categories of relevant articles within the literature that represent three distinct approaches to addressing gaps in health equity for IS research and practice.</p> Results <p>The first category brings attention to the importance of health equity in IS but remains strongly situated in the commonly accepted, mostly positivist methods and concepts of IS. The second set of articles broadens the perspective on structural factors relevant to health equity in IS, encouraging innovations of focus that hold greater potential to impact upon the social determinants of health. The third and final category includes articles that center concepts from the critical social sciences, such as intersectionality, to interrogate taken-for-granted beliefs in the field of IS, aiming to advance IS through social justice.</p> Conclusions <p>We propose a learning pathway for IS researchers, practitioners, and educators that progresses from acknowledging the need for explicit emphasis on health equity in IS toward the integration of critical social theory to advance health equity for population groups marginalized by differential axes of inequities such as class, gender, ethnicity/race, (dis)abilities and others. Such a learning pathway points toward a paradigm shift, inviting deeper critical reflection about the roles that power and oppression play in shaping IS in research and practice. This paradigm shift would lead to a stronger emphasis in IS on mitigating systemic oppression and marginalization of population groups most affected by health and social inequalities and healthcare inequities.</p>