<p>This paper investigates pricing, production, and online distribution mode choices in a green e-commerce supply chain with a conventional manufacturer, a green manufacturer, and an e-commerce platform. We develop a game-theoretic model in which two manufacturers choose between agency selling and reselling, while consumers exhibit heterogeneous preferences for functional quality and environmental consciousness. Consumer demand is derived from utility-based choice with an outside option, and platform green marketing is modeled as an additive enhancement to green utility when the platform resells the green product. By solving four mode configurations via backward induction, we obtain closed-form decisions and identify threshold conditions under which prices, quantities, and profits change monotonically or non-monotonically with consumer environmental consciousness and the green product’s functional quality. We show that (i) higher environmental consciousness intensifies price competition and can compensate for low functional quality of the green product, (ii) platform green marketing under reselling can increase the green product price while reducing the conventional product price, and (iii) win–win outcomes between two parties may arise, whereas a win–win–win outcome is generally difficult to achieve. An extension with endogenous platform green marketing and welfare-related implications suggests that the main channel-choice insights remain robust, while platform-led green promotion does not always improve environmental performance and may reduce welfare when markup extraction dominates demand expansion. These findings offer implications for platforms in structuring fees and developing marketing policies, and for manufacturers in aligning mode selection and pricing strategies with consumers’ environmental preferences and product-quality positioning.</p>