According to the United States Census Bureau, the town has a total area of , of which are land and , or 14.01%, are water. Ware lies at the southern end of the Quabbin Reservoir and the Quabbin Reservation. The reservation lands within town include two islands, the former Little Quabbin Hill and Mount Lizzie, neither of which were covered by the waters of the reservoir. The Swift River forms the western boundary of the town, and the Ware River flows through the southeastern part of the town, meeting in Palmer to form the Chicopee River (along with the Quaboag River), which flows into the Connecticut River. The lands of Ware are hilly between the valleys of the Swift and Ware rivers, and much of the land not surrounding the central part of town is heavily forested, with marshes lining the Ware River in spots. Along the Swift River lies the Herman Covey–Swift River Wildlife Management Area.