Background <p>Increasing attention to political and commercial determinants of health may have unintentionally overshadowed ecological determinants, while persistent conceptual ambiguity between ecological determinants of health (EclDoH) and environmental determinants of health (EnvDoH) may limit clarity for research, policy, and practice. This systematic review aimed to synthesise how EclDoH are defined and conceptualised in the academic literature, identify the components described, and examine their relationships with other determinants of health, particularly environmental determinants, at a global level.</p> Methods <p>We conducted a systematic review in accordance with PRISMA 2020 guidelines. Peer-reviewed publications explicitly addressing EclDoH and providing definitions, components, or relationships with other determinants were eligible; non-English and non–peer-reviewed publications were excluded. A comprehensive search of Scopus, PubMed, and EBSCOhost (including CINAHL, MEDLINE and PsycInfo databases) was undertaken for peer-reviewed publications available up to 16 September 2025, with additional studies identified through citation chaining and targeted Google Scholar searches. As the aim was to synthesise definitions, conceptualisations, and relationships, formal risk-of-bias tools were not applied. Definitions and relationships were synthesised narratively, while components were analysed using an inductive thematic approach. The study was funded by the Provincial Secretariat for Higher Education and ScientiicResearch of the Autonomous Province of Vojvodina, Republic of Serbia.</p> Results <p>A total of 100 publications were included, predominantly from high-income countries, particularly Canada (24%), the United States (13%), and Australia (12%). Just over half were original research articles, with the remainder comprising reviews, commentaries, book chapters, and conference papers. Only 16 publications (16%) explicitly defined EclDoH, most commonly framing them as systems and processes related to ecosystems, nature, and the non-human environment, often emphasising human–non-human interdependence. Components were identified in 94 publications and grouped into seven domains: physical environment, climate and weather, ecosystem, natural disasters, housing and urbanisation, food, and social environment, with the physical environment most frequently reported. Relationships with other determinants were described in 31 publications: 10 distinguished EclDoH from environmental determinants, 8 treated them as synonymous, and the remainder described interactions, particularly with social determinants of health.</p> Discussion <p>This review has found there is an absence of conceptual consensus on ecological determinants of health. This may limit comparability across studies and constrain effective research, advocacy, policymaking, and education. Greater conceptual clarity is essential to strengthen public health responses in the context of accelerating ecological change. Limitations: only English-language publications were included, and grey literature was notexamined. </p>