Lechaschau is a municipality in the district of Reutte, in the Austrian state of Tyrol. It lies in the Außerfern, the part of Tyrol that sits in the Alps of western Austria, close to the border with Germany.
The village is situated in the Lech valley near the town of Reutte, the administrative centre of the district. This part of Tyrol is characterised by its mountainous Alpine setting and its position on the Lech river, which flows through the region.
As a municipality, Lechaschau forms part of the local administrative structure of the Reutte district. It is one of a number of small communities in the surrounding valley area.