The Rhein-Haard-Express (RE 2) is a Regional-Express service in the German state of North Rhine-Westphalia (NRW), running from Osnabrück via Münster, Recklinghausen, Gelsenkirchen, Essen and Duisburg to Düsseldorf.

With the timetable change on 12 December 2010 there was another exchange of routes with the Duisburg–Mönchengladbach section operated by the Rhein-Hellweg-Express (RE 11), which now runs hourly between Hamm and Mönchengladbach.

Instead, the Haard-Bahn (RB 42), which previously ran between Münster and Essen on the same route as the Rhein-Haardt-Express, was extended to Mönchengladbach and renamed the Rhein-Haard-Express (RE 42).

At the timetable change in December 2019, the Rhein-Haard-Express on the Münster–Essen section was accelerated by skipping stops and extended to the Lower Saxony regional centre of Osnabrück.

At the same time, the Niers-Haard-Express began operating at half-hourly intervals on this section, stopping at all intermediate stations.

The RE 2 is operated by DB Regio AG, using push-pull trains of five double-deck carriages hauled by class 146 electric locomotives at speeds of up to 160 km/h.

The Rhein-Haard-Express connects in Munster, Gelsenkirchen, Essen, Duisburg and Düsseldorf with other transport services.