Nieuwleusen (Low Saxon: Ni'jlusen) is a town in the Dutch province of Overijssel with 5,913 inhabitants as of 1 January 2007. At the 2001 municipal reform, most of the former municipality of Nieuwleusen was incorporated into the municipality of Dalfsen. Part, including the Lichtmis area, was added to the municipality of Zwolle.

The provincial road N377 (the 'Den Hulst') runs along the town, going from Hasselt in the west to Coevorden in the east. To the north are the hamlet of Punthorst and the Staatsbos state woodland in the municipality of Staphorst. South of Nieuwleusen is Dalfsen, a slightly bigger town from which the municipality takes its name. To the west, provincial road N377 and highway A28 meet at De Lichtmis, the location of a former military bulwark which provided access to the north of the country. Nieuwleusen is situated between the Vecht and Reest rivers to the south and north respectively, and is counted as part of the historical region of Salland, or latterly the (Overijssels) Vechtdal (Vecht Valley - a usage in tourism).