CityNightLine AG (timetable and platform sign abbreviation: CNL) was a Swiss night train service.

CNL had right of passage grants in Germany, the Netherlands, Austria, Switzerland and Denmark.

It served stations in Belgium, France, Italy and the Czech Republic.

At the end of 2016, CityNightLine stopped operating, carriages were sold to the Austrian Railways which extended their night train network under the brand Nightjet.

Nightjet trains still connect Munich, Vienna, Zurich, Hamburg, Cologne, Berlin, Milan, Rome and other cities.