Thurbo is a railway company with mostly S-Bahn-style services in Switzerland (cantons of Aargau, Grisons, Schaffhausen, St. Gallen, Thurgau, Zürich), southern Germany (states of Baden-Württemberg, Bavaria), and northwestern Vorarlberg, Austria, jointly owned by Swiss Federal Railways (90%) and the canton of Thurgau.

As of 2022,[1] the company owns 110 Stadler GTW EMUs and carries 25.8 million passengers a year.

Thurbo was founded in September 2001 by Swiss Federal Railways (SBB CFF FFS) and Mittelthurgau-Bahn (MThB).

Infrastructure Kreuzlingen - Weinfelden - Wil SG, taken over from Mittelthurgau-Bahn, is operated by Thurbo but maintained by SBB CFF FFS.

Some lines are part of the Bodensee S-Bahn, which includes transborder services between Switzerland and southern Germany (Baden-Württemberg, Bavaria), some operated by SBB GmbH using EMUs of Thurbo , and Austria (Vorarlberg).