The Lake Thun railway line is a railway line in the Swiss canton of Bern. It links the towns of Thun, Spiez and Interlaken, running principally along the southern shore of Lake Thun. The line was opened in 1893 by the Lake Thun Railway company, but incorporates much of the earlier Bödeli Railway dating back to 1872.

Spiez is a town and municipality on the shore of Lake Thun in the Bernese Oberland region of the Swiss canton of Bern. It is part of the Frutigen-Niedersimmental administrative district. Besides the town of Spiez, the municipality also includes the settlements of Einigen, Hondrich, Faulensee, and Spiezwiler.