Glacier reconstruction typically aims to establish the former extent of ice masses at any given period. Such reconstructions are important because they provide crucial information about past (palaeo) glacier changes over much longer timescales than the observational record permits. Reconstructing the dimensions and dynamics of palaeo-ice masses enables equilibrium line altitudes, and temperature or precipitation to be calculated, making glaciers an important palaeo-climate proxy. Given this utility, geomorphologically-based glacier reconstructions have been generated for many regions globally, although the specific methods employed are rarely described formally. To address this shortcoming, this chapter describes some of the methods employed in generating geomorphologically-based reconstructions for ice sheets and mountain-scale glaciers (< ~1,000 km2)