'Lake Zürich-Gotthard Railway'; ZGB) is a 3.51 km (2.18 mi) long, mostly single-tracked standard-gauge railway line connecting Pfäffikon in the Swiss canton of Schwyz with Rapperswil in the canton of St. Gallen, crossing Lake Zürich using the Hurden peninsula and Seedamm causeway.

The Zürichsee–Gotthardbahn (which is listed in Swiss federal statistics as the Rapperswil–Pfäffikon company) commenced operations over the newly built Seedamm (causeway) from Rapperswil to Pfäffikon on 27 August 1878.

The federal government contributed 100,000 francs to the cost of the causeway construction, which included a road (Hauptstrasse 8) and a footpath as well as the railway.

The operations, which always ran at a deficit, stopped at Rapperwil, where the ZGB connected with the Lake Zürich left-bank railway.

When another initiative committee tried to get a concession for a Pfäffikon–Brunnen or Pfäffikon–Arth-Goldau railway, the ZGB sold it the land surveys that it had already carried out.