Forests are defined in many different ways. Apart from ecological and structural factors, associated values and provided ecosystem services are an important part of forest definitions. Typically, forest types are differentiated based on climatic regions and on degrees of human modification. A better understanding of how to distinguish different forests on the basis of the values they provide is needed to advance global policies put forward by organizations such as the Convention on Biological Diversity (CBD), the United Nations Framework Convention on Climate Change (UNFCCC), or the UN Sustainable Development Goals (SDGs). These policies so far approach all forests in a similar manner, regardless of their condition. Without this distinction, benefits stemming from forest intactness and their contribution to global environmental challenges remain unaccounted for. Forest definitions provide the basis for policies and monitoring systems driving or enabling deforestation, degradation, reforestation, and restoration. Here, we provide a systematic approach to disentangle and synthesize different value classifications of forests. As part of a collaboration between ETH Zurich, the French Agricultural Research Centre for International Development (CIRAD), the University of Liège and Biotope, Forest Stewardship Council International (FSC) commissioned a systematic map that aims to clarify how definitions of forests of high value are understood and described. Focusing on forests of high value, the systematic map will address three research questions: (1) How are various terms linked to forests of high value defined in the literature?; (2) Do definitions vary between different actors?; and (3) How common are the various definitions? Bibliographic databases and organizational websites will be searched, and internet search engines used to find relevant peer-reviewed and grey literature. The searches will be conducted in English, French, and Spanish. Data extraction and coding will be performed at the same time when full texts are considered for inclusion. Definitions will be extracted as well as their respective sources and other study information. We will produce a catalog of definitions for different terms associated with forests of high value, a narrative synthesis describing the evidence base, and visualizations illustrating the relationships between definitions and terms for forests of high value and their frequencies in the literature.