Studies of ice extent, volume, and dynamics during former glaciations are important for understanding past climates and evolution of the Earth's surface, and they also provide analogies for present-day and future ice sheets and their subglacial environments. The special issue (SI) "Icy landscapes of the past" brings together contributions from four Copernicus journals (Climate of the Past, The Cryosphere, Earth Surface Dynamics, and Earth System Science Data), reflecting the interdisciplinarity across scientific communities working with former glaciations from the perspectives of palaeoclimatology, glacial geomorphology, Quaternary geology, and numerical modelling, among others. It provides a platform from which field-based reconstructions and model simulations can be compared and contrasted, teasing out complex couplings between the changing cryosphere-induced topographic, freshwater, and sea level forcings and climate states of both warmer and colder epochs of the past. Through this SI, we aim to piece together the growing knowledge about regional responses of different geographic regions to past climate changes to obtain a global picture, thereby fostering emerging collaborations between previously disconnected geoscientific disciplines. We welcome contributions that shed light on ancient and more recent glaciations on Earth and their interaction with other components of the Earth system.