Spreitenbach (High Alemannic: Spräitebach) is a municipality in the district of Baden in the canton of Aargau in Switzerland, located in the Limmat Valley (German: Limmattal).

The old town center, through which the Spreitenbach stream flows, lies to the south and has preserved its original character well.

North of that is the modern city, with wide apartment buildings, industrial areas, and shopping centers.

The extended industrial zone Neuhard is located to the extreme north, across the motorway and railway, at a bend in the Limmat.

The Franzosenweiher ("French pond") lies in the forested area south of Spreitenbach, near the municipal border with Dietikon.

The "Altes Bad" biotope is made up of a pool and a wetland with a great diversity of plants.

The name comes from the fact that Napoleon's troops camped at the pond, before crossing the Limmat at Kloster Fahr.

Of the rest of the land, 35.5% is settled (buildings or roads) and the remainder (1.4%) is non-productive (rivers or lakes).

The citizens of Spreitenbach lobbied for the path to go far to the side of the city; for this reason, the nearest station today is in the municipality of Killwangen, although it has about seven times fewer residents.

This was in addition to the general housing demand, which rose due to the population growth of the Zurich area.

It was planned as a satellite city: a string of high-rise developments and designated commercial and industrial zones.

The blazon of the municipal coat of arms is: "Geviert von Blau mit gekröntem gelbem Leopardenkopf und von Rot mit sechsstrahligem weissem Stern" ("Quarterly, Azure, a crowned leopard head Or; Gules, a six-pointed star Argent").

The leopard head alludes to the Schönenwerd nobility, and the star to the Wettingen Abbey, the former judges.

As their principal language 72.1% spoke German, 7.0% Italian, 6.1% Serbo-Croatian, 4.8% Albanian, 2.3% Turkish, 1.2% Spanish, and 1.1% each French and Portuguese.

The council represents and leads the municipality, and for that purpose execute the resolutions of the assembly and the responsibilities assigned by the canton and the federation.

The five members of the municipal council for the 2006–2009 term are: Legal disputes are handled by the Baden court.

Several leading companies operate in Spreitenbach; the most notable are Zweifel Pomy-Chips (potato chips), Bridgestone (car tires), Johnson & Johnson (pharmacy/cosmetics), Nestlé (foodstuffs), Miele (household goods), and Globus (retail trade).

In Spreitenbach and its neighbor Dietikon, the largest classification yard of the region was built in 1978 (later expanded), the Rangierbahnhof-Limmattal (RBL).

The lines 2, 4, and 8 of the Regionale Verkehrsbetriebe Baden-Wettingen go in the direction of Killwangen, Neuenhof, Wettingen, and Baden.