Last-mile logistics is both a source and cause of problems in urban areas, especially problems related to traffic congestion, unsustainable delivery modes, and limited parking availability. In this context, multiple sustainable logistics solutions have been proposed. We focus on micro-depots (MDs), which can function as a consolidation center and a collection-and-delivery point for business-to-consumer (B2C) small parcels. This paper presents a new research idea that extends the existing MD solution by introducing the concept of a shared MD network with parcel lockers. Such networks enable multiple logistics service providers (LSPs) and/or business partners to use an MD while minimizing their individual costs and optimizing the use of urban space. We present case studies of such shared MD networks operating in the cities of Helsinki and Helmond. We provide a framework for auxiliary businesses that can exploit the existing MD structure to offer services to the surrounding population. Finally, we define metrics for evaluating the success of shared MD networks while considering social, environmental and economic objectives. The case studies highlight the complexity of implementing such a solution; it requires stakeholders’ involvement and collaboration. In particular, deciding on the location for a shared MD network is a critical phase, since local authorities have their own regulations, and residents’ preferences are usually different than LSPs’ ones. Nevertheless, if these challenges are overcome, this sustainable last-mile logistics solution has a promising future.