Steinmaur is a municipality in the district of Dielsdorf in the canton of Zürich in Switzerland.

Situated in the Wehntal, Steinmaur has an area of 9.5 km2 (3.7 sq mi).

Of the rest of the land, 12.9% is settled (buildings or roads) and the remainder (0.5%) is non-productive (rivers, glaciers or mountains).

Most of the population (as of 2000[update]) speaks German (88.5%), with Italian being second most common ( 2.1%) and Albanian being third ( 1.9%).

In the 2007 election the most popular party was the SVP which received 40% of the vote.