The Sieg Railway (German: Siegstrecke is a 100-kilometre long, electrified German main line railway between Cologne-Deutz via Porz, Troisdorf, Siegburg, Hennef, Au, Betzdorf to Siegen with a through service to Cologne Hauptbahnhof. Although most of it is two-track, two five-kilometre sections are only single track. Both ends of the line are in the state of North Rhine-Westphalia, but between Au and Niederschelden it runs through Rhineland-Palatinate. It is one of the oldest lines in Germany, opened between 1859 and 1862 by the Cologne-Minden Railway Company.

Köln Messe/Deutz station is an important railway junction for long-distance rail and local services in the Deutz neighborhood of Cologne in the German state of North Rhine-Westphalia. It is situated close to the eastern bank of the Rhine and connected via the Hohenzollern Bridge to Köln Hauptbahnhof, the city's main station, which is just a few hundred metres away. The Cologne Trade Fair grounds are directly north of the station, hence the Messe in the station's name. The Deutz/Messe station of the Cologne Stadtbahn is nearby and connected to this station by a pedestrian tunnel.