Elsau is a municipality in the district of Winterthur in the canton of Zürich in Switzerland.

[3] On 23 April 1398 Count Donat von Toggenburg, Herr zu Brettengow und Tavas donated the church of Elsow as benefice for the new Allerheiligenaltar at the grave of the Toggenburg family in the Rüti Monastery, for the salvation of the soul of his daughter Menta von Toggenburg who died shortly before, as well as further lands and goods in the present Weinland district of the canton of Zürich, confirmed among others by Ruodolf von Bonstetten from Ustra.

Of the rest of the land, 17.2% is settled (buildings or roads) and the remainder (0.6%) is non-productive (rivers, glaciers or mountains).

As of 2007[update] 15.4% of the total municipal area was undergoing some type of construction.

Most of the population (as of 2000[update]) speaks German (93.0%), with Italian being second most common (1.3%) and Albanian being third (1.3%).

[6] The historical population is given in the following table:[3] The railway stations of Räterschen and Schottikon both lie within the municipality of Elsau.