Facilitated by ITU, twelve partners from the public and private sectors, academia and civil society share their experience, knowledge and expertise, providing an aggregated, harmonised set of principles on the development, establishment and implementation of national cybersecurity strategies. The guide’s objective is to instigate strategic thinking and help national leaders and policy-makers to develop, establish and implement national cybersecurity strategies world-wide. The National Cybersecurity Strategy Guide was developed through an iterative approach, which sought to reach agreement through consensus-building. It is based on existing resources and aims to facilitate its use by national stakeholders. Wherever possible, the relevant sources and tools used to develop each set of recommendations are listed in the Reference section to encourage their broader use. Cybersecurity is a foundational element underpinning the achievement of socio-economic objectives of modern economies. The hope is that the resulting National Cybersecurity Strategy Guide can serve as a useful tool to all stakeholders, including national policy-makers, legislators and regulators, with cybersecurity responsibilities. In addition, it might have broader applicability, as the concepts introduced can be applied at the regional, or municipal levels, as well as adapted for industry.