|TG is the abbreviation for the canton of Thurgau in Switzerland and is used to avoid confusion with other entries of the name Au .|
|Canton :||Thurgau (TG)|
|Political community :||Fischingen|
|Postal code :||8376|
|former BFS no. :||4726|
|Area :||10,55 km²|
|Population density :||26 inhabitants per km²|
Au is a village  of the political municipality Fischingen in the Münchwilen district of the canton of Thurgau in Switzerland . The scattered settlement on the Hörnli includes a valley settlement with a church and numerous hamlets and farms in the foothills of the Alps.
Au was first mentioned around 1160/70 as Ovwun (?) And in 1275 as in der Owe. In the 11th / 12th In the 19th century a Marienkapelle was built, which belonged to the parish of Dussnang . After Dussnang was incorporated into Fischingen Monastery in 1244, Au was supplied from the monastery, which also held the jurisdiction until 1798 . A Catholic parish has existed since 1852, while the Protestant residents belong to the parish of Dussnang.
The most important branch of business after the abandonment of agriculture was livestock. In 1887 a cheese dairy was established. The weaving and embroidery offered temporary additional purchases, but could not prevent poverty and continuous emigration.
Of the total of 137 inhabitants in the village of Au in 2018, 87 (63.5%) were Roman Catholic and 30 (21.9%) were Protestant Reformed. 
- Swiss land use statistics. Completed on July 1, 1912. Published by the Federal Statistical Bureau. ( Memento from April 12, 2016 in the Internet Archive )
- Gregor Spuhler: Au (TG). In: Historical Lexicon of Switzerland .
- Localities and their resident population. Edition 2019 . On the website of the Statistical Office of the Canton of Thurgau (Excel table; 0.1 MB), accessed on April 28, 2020.