Onderdendam is a village in Het Hogeland municipality in the province of Groningen, the Netherlands. It had a population of around 600 in January 2017.
The corn mill Hunsingo, also known as Molen van Haitsma, is located at Boterdiep in Onderdendam in the province of Groningen. The mill was built in 1855 and operated on wind power until 1939. Then the mill was stripped of its hood, blades, scaffolding and superstructure. Only the octagonal stone substructure remained.