Background: E-commerce growth has intensified last-mile logistics, a stage often described as the final leg from a distribution hub to the customer and frequently cited as a disproportionate share of total delivery cost. This review evaluates operational strategies that improve efficiency while reducing emissions, framing the problem as a coupled cost–carbon optimization. Methods: We synthesize work on last-mile delivery, consolidation, micro-fulfillment, electrification, and cargo-bike deployment, and propose a decision framework linking service promises to routing and fleet choices. Results: Interventions that combine consolidation with low-emission modes can reduce emissions without sacrificing service, but they require urban infrastructure and governance of delivery windows and pickup options. Conclusions: Sustainable last-mile performance is achieved through network design (where to stock), operational control (how to route), and demand shaping (how customers choose speed and delivery format).