Løgstør is a town with a population of 4,284 (1 January 2014) and a former municipality (Danish, kommune) in Region Nordjylland on the Jutland Peninsula in northern Denmark. The municipality, including the island of Livø, covered an area of , and had a total population of 10,270 (2005). Its last mayor was Jens Lauritzen, a member of the Venstre (Liberal Party) political party.
A bridge connects the former municipality near Tolstrup to the town of Aggersund on the far side of the Agger Strait.
The island of Livø lies off the former municipality's western shores, and is partially a protected nature reserve.
On 1 January 2007, Løgstør municipality ceased to exist as a result of Kommunalreformen ("The Municipality Reform" of 2007). It was merged with Farsø, Aalestrup, and Aars municipalities, to form the new Vesthimmerland municipality, with an area of and a total population of 39,176 (2005).