Bichlbach is a municipality in the district of Reutte in the Austrian state of Tyrol.

Bichlbach lies at an elevation of 1,079 m (AA) in the Zwischentoren, the valley that links the Ehrwald Basin with the Lech valley. Over the municipal territory runs the watershed between the Lech and Loisach. The municipality consists of three villages: the elongated Straßendorf of Bichlbach (1,079 m above sea level (AA), population: 550) and the two almost adjacent villages of Lähn (1,112 m above sea level (AA), pop: 225) and Wengle (1,083 m above sea level (AA), pop: 76; population figures as of 15 May 2001). Bichlbach is the base for an ascent of the Kohlbergspitze (2,202 m) on a waymarked path that takes around 3 hours.

The municipal area comprises the following three villages (population as of 1 January 2019):

The settlement took place from the Allgäu.