In polygynous ungulates, males may achieve fertilization through the use of alternative reproductive tactics (ARTs), discrete phenotypic variations evolved to maximize fitness. ARTs are often associated with different male spatial strategies during the rut, from territoriality to female-following. Although variation in space use patterns of rutting male ungulates is known to be largely affected by the spatial distribution of females, information on the year-round habitat selection of alternative reproductive types is scant. Here, we investigate the seasonal variation in habitat choice of a large mammal with ARTs (territoriality and non-territoriality), the Northern chamois Rupicapra rupicapra. Global Positioning System (GPS) data on 28 adult males were collected between February 2010 and December 2013 in the Gran Paradiso National Park (Italy), and used to fit resource selection functions to explore the ART-specific use of key topographic features such as elevation, aspect and slope, and vegetation phenology expressed as NDVI values. Territorial and non-territorial chamois profoundly differed in their habitat selection not only during the rutting season. Compared to non-territorial males, territorial males used lower elevations in summer and autumn, preferred southern slopes in spring and summer, and used steeper areas in summer but not in winter. We found no difference in seasonal selection of NDVI values between males adopting ARTs. Our results suggest that territorial males tend to occupy warmer, lower-food-quality habitats in late spring and summer, whereas non-territorial males are free to follow and exploit vegetation phenology and more favourable temperatures. Different patterns of habitat selection may reflect different trade-offs between the optimisation of energy balances throughout the year and the increase of mating opportunities during the rut in males adopting alternative reproductive tactics.