Oldenzaal (Dutch pronunciation: [ˈɔldə(n)ˌzaːl] ⓘ; Tweants: Oldnzel) is a municipality and a city in the eastern province of Overijssel in the Netherlands.

It is part of the region of Twente and is close to the German border.

Located on the A1 motorway from Amsterdam to Germany, Oldenzaal also has a rail connection to Hengelo and Bad Bentheim.

During the carnival season Oldenzaal is known as "Boeskool-stad" which is a local dialect of the word Cabbage-town.

The town is served by the Oldenzaal railway station.