["Corporate Social Responsibility and Environmental Management, Volume 33, Issue 2, Page 1970-1985, March 2026. ", "\nABSTRACT\nThis study examines how the CEOs of small and medium‐sized enterprises (SMEs) navigate decarbonisation under stakeholder demands and resource constraints. Drawing on 22 interviews with French SME leaders, we inductively derive three responses, namely, opportunistic, analytic, and systemic, that align with the SME‐adjusted version of the corporate social responsibility maturity model of Karwowski and Raulinajtys‐Grzybek. We integrate stakeholder agency theory, the resource‐based view, and institutional theory into a framework to explain how external pressures and internal capabilities, mediated by CEO sensemaking and stance, shape these responses. Opportunistic firms act tactically with post hoc green narratives, analytic firms measure and optimise via key performance indicators, and systemic firms embed life cycle thinking while redesigning their offerings or supply chains. We outline the practical levers (simplified tools, targeted incentives, and leadership training) that help firms transition from analytic to systemic responses. This study contributes to the SME‐sensitive theorisation of sustainability agency and provides a usable roadmap for low‐carbon transformation.\n"]