This guideline provides locally adaptable, clear, evidence-informed global recommendations on the fortification of wheat flour with vitamins and minerals as a public health strategy to improve the micronutrient status of populations, which are grounded in gender, equity and human rights approaches with the aim of leaving no one behind. The focus of this document is on the use of this intervention as a public health strategy and not on market-driven fortification of wheat flour or products. This guideline aims to help Member States and their partners to make informed decisions on the appropriate nutrition actions to achieve the 2030 Sustainable Development Goals and the global targets set in the World Health Organization (WHO) comprehensive implementation plan on maternal, infant and young child nutrition. The recommendations in this guideline are intended for a wide audience, including policymakers, expert advisers, and technical and programme staff in ministries and organizations involved in the design, implementation and scaling-up of nutrition actions for public health. The recommendations are particularly relevant to the design and implementation of appropriate food-fortification programmes, as part of a comprehensive food-based strategy for combating micronutrient inadequacies and deficiencies. These recommendations supersede the previous WHO recommendation on the fortification of wheat flour.