The Arctic Observing Summit (AOS) is a high-level, biennial summit that aims to provide community-driven, science-based guidance for the design, implementation, coordination and sustained long-term (decades) operation of an international network of arctic observing systems. The AOS will provide a platform to address urgent and broadly recognized needs of arctic observing across all components of the arctic system, including the human component. It will foster international communication and coordination of long-term observations aimed at improving understanding and responding to system-scale arctic change. The AOS will be an international forum for optimizing resource allocation through coordination and exchange among researchers, funding agencies, and others involved or interested in long-term observing activities, while minimizing duplication and gaps. The AOS is a contribution to the Sustaining Arctic Observing Network (SAON) initiative.