The Scottish Government aims to increase the rate of woodland expansion to achieve a range of economic, social and environmental benefits, including climate change mitigation. Following publication of its Land Use Strategy in 2011, the Scottish Government set up the Woodland Expansion Advisory Group (WEAG) to provide advice on which types of land are best for tree planting. This paper describes the methodology and results of the Woodland Expansion GIS Project which was commissioned to inform the Group. It identifies the types of land in Scotland which could hold the most potential for tree planting. Land was allocated into three categories (referred to as Phases) to indicate the level of constraint and, by default, of opportunity for expansion based on natural and policy constraints using national scale digital datasets. The results show that Scotland has the capacity for increasing its woodland cover across a range of land types. The potential for new woodlands in each of the three categories of land is discussed.