As global maritime logistics contribute approximately 3% of global greenhouse gas emissions, innovative strategies are needed to address the environmental impact of port and shipping operations. This study examines VINCI Energies, an international engineering firm specializing in energy infrastructure, and explores how it integrates circular economy principles into sustainable maritime logistics. The paper also investigates Port Tampa Bay's current and potential initiatives related to circular economy practices, including the prospective adoption of Onshore Power Supply (OPS) systems. By focusing on solutions such as OPS systems, reverse logistics, digitalization, port symbiosis, modular design, and waste valorization, VINCI Energies offers a replicable model for reducing emissions and optimizing resource use. This study employs case analysis, comparative literature review, and feasible recommendations to connect global best practices with local opportunities. It concludes with a roadmap that Port Tampa Bay and similar ports can adopt to improve circularity, efficiency, and environmental sustainability.