Railjet is a high-speed rail service in Europe operated by Austrian Federal Railways (ÖBB) and Czech Railways (ČD). Branded as Railjet Express (RJX) for the fastest services and as Railjet (RJ) for services with additional stops, it was introduced in 2008 and operates at speeds of up to 230 km/h (143 mph). Railjet is ÖBB's premier service and operates both domestically within Austria and on international services to adjacent major cities in the Czech Republic, Germany, Switzerland, Italy, Hungary and Slovakia.

The Austrian Federal Railways, now commonly known as ÖBB, is the national railway company of Austria, and the administrator of Liechtenstein's railways. The ÖBB group is owned entirely by the Republic of Austria, and is divided into several separate businesses that manage the infrastructure and operate passenger and freight services.