The Stuttgart–Wendlingen high-speed railway is a proposed German high-speed line to be built as part of the Stuttgart 21 project. It runs from Stuttgart Hauptbahnhof via the to the Filder plain and from there to the Neckar valley at Wendlingen, where it runs on to the Wendlingen–Ulm high-speed line. It is part of the Paris-Budapest axis as defined by the European Union. The line would connect the new via the , and another line would connect to the existing airport station.