Reinach is a municipality in the district of Kulm in the canton of Aargau in Switzerland.

Scattered neolithic items indicated that the area around Reinach has been occupied since at least that time.

[3] Ecclesiastically, before the Protestant Reformation in 1528, Reinach belonged to the parish of Pfeffikon.

After it converted to the new denomination, a new parish was formed with Menziken, Beinwil am See, Burg and Leimbach.

The Wynental- und Suhrentalbahn connected the municipality in 1904 to Aarau as part of the Reinach-Menziken line.

Merger negotiations with neighboring communities in the upper Wynental were suspended because of little financial participation by the canton.

[3] Reinach has an area, as of 2009[update], of 9.47 square kilometers (3.66 sq mi).

[4] The municipality is located in the Kulm district, in the upper Wynental (Wyna river valley).

The blazon of the municipal coat of arms is Or a Lion rampant Gules with head and tongue Azure.

[8] The age distribution, as of 2008[update], in Reinach is; 783 children or 9.9% of the population are between 0 and 9 years old and 1,002 teenagers or 12.7% are between 10 and 19.

[8] From the 2000 census[update], 2,070 or 28.5% were Roman Catholic, while 3,283 or 45.2% belonged to the Swiss Reformed Church.