Sisseln is a municipality in the district of Laufenburg in the canton of Aargau in Switzerland.

Sisseln has an area, as of 2009[update], of 2.52 square kilometers (0.97 sq mi).

Most of the population (as of 2000[update]) speaks German (91.9%), with Italian being second most common ( 2.4%) and French being third ( 0.9%).

[7] The age distribution, as of 2008[update], in Sisseln is; 149 children or 11.3% of the population are between 0 and 9 years old and 145 teenagers or 11.0% are between 10 and 19.

[7] In the 2007 federal election the most popular party was the SVP which received 40.9% of the vote.

[9] The historical population is given in the following table:[8] As of  2007[update], Sisseln had an unemployment rate of 2.16%.

[7] From the 2000 census[update], 563 or 44.7% were Roman Catholic, while 380 or 30.2% belonged to the Swiss Reformed Church.