The Wil–Kreuzlingen railway is a largely single-track standard-gauge line in northeastern Switzerland. It was built by the Mittelthurgaubahn; MThB), which was a Swiss private railway based in Weinfelden. It was liquidated in 2003, including its subsidiary Lokoop, and its activities and the infrastructure it owned were mainly taken over by a Swiss Federal Railways (SBB) subsidiary, Thurbo, which was originally formed as a joint venture between the MThB and the SBB.