Innerthal is a municipality in March District in the canton of Schwyz in Switzerland.

Of the rest of the land, 0.4% is settled (buildings or roads) and the remainder (30.6%) is non-productive (rivers, glaciers or mountains).

Most of the population (as of 2000[update]) speaks German (97.0%), with Italian being second most common ( 1.8%) and Rhaeto-romance being third ( 0.6%).

[4] From the 2000 census[update], 156 or 93.4% are Roman Catholic, while 8 or 4.8% belonged to the Swiss Reformed Church.

The wettest month is June during which time Innerthal receives an average of 284 mm (11.2 in) of precipitation.

The driest month of the year is October with an average of 131 mm (5.2 in) of precipitation over 17.1 days.