Home range and activity patterns of animals are important elements for wildlife management and conservation practices. We examined seasonal home range and daily activity patterns of the endangered Swayne's hartebeest (Alcelaphus buselaphus swaynei) in Maze National Park, Ethiopia. We tracked two groups of Swayne's hartebeests in open grassland for 1 year. Each group's daily activities (0700–1900 h) and GPS locations were recorded at 15-min intervals on 5 days every month. Activities were grouped into five behavioral categories: feeding, resting, traveling, vigilance, and other. In addition, we carried out nocturnal monitoring during full moon periods to further document movements patterns. We produced 95% and 50% kernel density estimates (KDE) of home range sizes for each group. Home range estimates did not vary across seasons. Feeding and traveling peaked during the early morning and late afternoon, whereas resting occurred most frequently during the midday hours in both seasons. The proportion of time spent feeding was higher during the dry season, whereas a greater proportion of time was spent resting during the wet season. Vigilance behavior occurred consistently throughout the day during both seasons. Time spent feeding and traveling did not vary significantly between seasons. Activity patterns of Swayne's hartebeests are strongly influenced both by time of day and season, while home range size is less influenced by seasonality and may instead reflect temporal variation in food availability. Our findings will help to inform management strategies and conserve one of the last two extant populations of Swayne's hartebeests.