Winchendon is a town located in Worcester County, Massachusetts, USA. It was first settled in 1753 and was officially incorporated in 1764.
According to the United States Census Bureau, the town has a total area of 114.1 km² (44.1 mi²). 112.1 km² (43.3 mi²) of it is land and 2.0 km² (0.8 mi²) of it is water. The total area is 1.77% water.