Hydro-geomorphic connectivity has emerged as a significant conceptual framework for understanding the transfer of surface water and materials (e.g. sediment, plant propagules, and nutrients) through landscapes. The concept of connectivity has had particular success in the fields of catchment hydrology, fluvial geomorphology and soil erosion, but has also been employed in, for example, studies of hydrochory. Connectivity as applied in various disciplines can be a transformative concept in understanding complex systems, allowing analyses of how such systems behave in terms of scaling, catastrophic/phase transitions, critical nodes, emergence and self-organization, e.g. by applying network-based analyses and modelling. Recent research also highlights the widespread nature of disconnectivity in river and catchment systems, caused by natural and anthropogenic structures including dams, log jams, or agricultural terraces. These and other forms of disconnectivity can have large spatial and temporal implications on ecological, geomorphic, hydrological and biogeochemical processes through buffering water and material fluxes. We aim to create a diverse interdisciplinary session that reflects a broad range of research seeking to illustrate the role of (dis-)connectivity in river and catchment systems. We hope to use the session to develop a discussion of the dual roles of connectivity and disconnectivity to generate a basis for an integrated framework to be applied across different fields of geosciences and for managing river and catchment systems.