Ottenbach is a municipality in the district of Affoltern in the canton of Zürich in Switzerland.

[3] Since the end of the 18th century, the textile industry had expanded as a home industry (Putting-out system) in Ottenbach: In 1784, the cotton spinning mill employed 49% of the local population (430 people, 287 of whom worked all year round).

Of the rest of the land, 19.1% is settled (buildings or roads) and the remainder (3.8%) is non-productive (rivers, glaciers or mountains).

It produced current for operating looms of the silk weaving factory A.F.

Most of the population (as of 2000[update]) speaks German (93.6%), with Italian being second most common ( 1.7%) and English being third ( 1.0%).