Growing spatial inequalities driven by urban-centric development models have deepened the marginalization of inland areas, resulting in demographic decline, loss of essential services, and diminished political agency. In response, territorial cohesion has emerged as a key objective within European policy, aimed at reducing regional disparities while promoting balanced and place-sensitive development. This chapter traces the evolution of the concept from its formal recognition in the Lisbon Treaty and critically assesses the principles underpinning territorial cohesion—spatial justice, polycentricity, and territorial diversity—while questioning the limitations of growth-oriented, space-blind policy frameworks. The Italian National Strategy for Inner Areas (SNAI) is examined as a significant policy experiment that redefines cohesion through place-based activation and negotiated multilevel governance. This chapter concludes by advancing a socio-ecological reframing of territorial cohesion, informed by the Nature’s Contributions to People (NCP) framework. This approach foregrounds the often-overlooked ecological functions of inland areas and their interdependencies with urban centers, opening the path toward a more systemic understanding of cohesion, grounded in the recognition of local specificities and territorial diversity.