The transition of agriculture towards sustainability faces significant obstacles, such as increased demand for food, food insecurity, climate variability, biodiversity loss, and food waste, among others. Moreover, agricultural activities must address ethical practices within sustainable development. The literature frequently mentions two approaches to meet these challenges: agroecology and sustainable agriculture. This study aims to delineate the conceptual boundaries of agroecology and sustainable agriculture while elucidating their interconnection. It seeks to clarify the scope and limitations inherent in these agricultural practices, which is critical given the centrality of sustainable agriculture in agrarian studies. By establishing these boundaries, the research outlines the methodologies to identify the relevant variables and indicators required for effective stakeholder engagement within agricultural systems. A systematic literature review was conducted using the PRISMA method. The databases searched were Science Direct, Scopus, Nature, and Google Scholar. The inclusion criteria were (i) written in English or Spanish, (ii) published in a peer-reviewed academic journal, and (iii) related to the conceptualization of agroecology and sustainable agriculture. Publications were selected following the method’s identification, screening, eligibility, and inclusion guidelines. The main distinctions between the concepts are the scale and the scope. Agroecology reveals limitations to achieving impacts on food security and agriculture’s challenges in a large-scale system better suited for rural communities and small farms seeking locally adapted solutions. On the other hand, the literature reveals that it is crucial to adopt a multi-scale systems approach to meet the growing food demands of the global population, for which sustainable agriculture may be more effective.