Rupperswil is a municipality in the district of Lenzburg in the canton of Aargau in Switzerland.

After the conquest of the Aargau in 1415 it became part of the Bernese District (German: Hochgerichtsbezirk) of Lenzburg.

Under the Bernese Bailiwick of Lenzburg, Rupperswil was the center of a lower court district.

[3] In the early 19th century the textile industry increasingly changed the formerly agricultural village.

Starting at the end of the 19th century there were more metal-processing plants and a sugar mill in Rupperswil.

Rupperswil has an area, as of 2009[update], of 6.21 square kilometers (2.40 sq mi).

[4] The municipality is located in the Lenzburg district, south of the Aare river.

The blazon of the municipal coat of arms is Argent a Bend Azure.

Most of the population (as of 2000[update]) speaks German (88.2%), with Italian being second most common ( 3.7%) and Serbo-Croatian being third ( 2.1%).

[8] The age distribution, as of 2008[update], in Rupperswil is; 433 children or 10.1% of the population are between 0 and 9 years old and 492 teenagers or 11.5% are between 10 and 19.

[8] In the 2007 federal election the most popular party was the SVP which received 39.6% of the vote.

[8] The historical population is given in the following table:[3] The Fabrikanlage (factory town) Rupperswil is designated as part of the Inventory of Swiss Heritage Sites.

[8] From the 2000 census[update], 969 or 25.7% were Roman Catholic, while 2,008 or 53.3% belonged to the Swiss Reformed Church.

The library has (as of 2008[update]) 8,404 books or other media, and loaned out 19,476 items in the same year.