As zero operational-cost variable Renewable Energy Sources are foreseen to dominate the future energy mix, the abundance of green electricity will allow the replacement of fossil fuels in sectors such as heating, cooling, industrial processes, and transport. The intermittency of such energy resources implies significant systemic requirements for flexible solutions; thus, developments of the energy sector in general, and the power system in particular, instigate significant innovation activities in the fields of power system flexibility. Concurrently, complexities and interdependencies of system components and multitude of actors increase the risks of service failures and the complexity of production and grid planning, raising the demand for stronger and more agile resilience means and countermeasures. In this white paper we discuss the item “How can flexibility support resilience?”, considering the increased societal needs of a secure electricity supply. Power system resilience reflects the impact of severe events and is an overarching concept, covering the whole spectrum of the power system from design and investment decisions to planning, operations, maintenance and asset management functions. As such, the concept of power system resilience applies to the planning time frame that looks to build resilience into the future network, as well as the operational time frame, in which security is managed by optimizing the inherent resilience of the existing power system. Flexibility concerns the power systems ability to manage changes, with flexibility features able to improve the resilience characteristics of the broader view system of systems, provided that they are integrated in grid planning, in defence plans, and properly evaluated in the energy market design. Flexibility capabilities need to be considered from the planning stage, using a holistic approach aimed at grids to be flexible and resilient by design. Flexibility resources can also facilitate the restoration process by exploiting distributed black start capabilities including sector-coupling, which adds a new dimension to the necessary interactions pattern between electrical TSOs and DSOs, with utilities from other sectors. Power system planning for the future grid must embrace a wide range of network and non-network options to create operational flexibility options, including more active demand management techniques and customer-sensitive smart load shedding procedures. The next level of flexibility is seen as being fully deployed and utilized for operation and planning of the power system, being integrated in procedures for long-term planning as well as in tools for stability support. The integrated dependency of flexibility directly impacts the resiliency of the power system, thus flexibility solutions intended to provide resilience support must be reliable and secure to provide the trust required for operation and planning. Many of the worldwide ongoing initiatives can provide highly relevant knowledge to the question of How can flexibility support resilience? Indeed, they show the relevance and the potential values to be unlocked, with potentially some low hanging fruits to start with. Some of the examined areas include: • System Integrity Protection Schemes • System Technical Performance • Alternative Grid Development The economic value provided by large scale flexibility solutions can increase the benefit of maintaining high levels of resilience and thus provide incentives for resilience-enhancing investments. Additionally, cyber security is an area with increased focus as part of the power system digitalisation. Finally, standardisation of solutions is important to increase the reliability & acceptance in order for large scale deployment of flexibility.