Wasserfluh Pass (el. 848 m.) is a mountain pass in the canton of St. Gallen in Switzerland.

It connects Lichtensteig and Brunnadern. The pass road has a maximum grade of 10 percent and an elevation gain of 345 m.

Overlooking the pass are the ruins of Neu-Toggenburg castle (47°19′47″N 9°06′46″E / 47.3296°N 9.1127°E / 47.3296; 9.1127), built by the counts of Toggenburg in the late 12th century (excavated 1937/8).