Monheim am Rhein in the Federal State of North Rhine-Westphalia (in the administrative district of Düsseldorf and the district of Mettmann) is located on the right (eastern) bank of the Lower Rhine (river kilometers 707 to 717). The medium-sized district town borders on Langenfeld to the east, Leverkusen to the south, Cologne and Dormagen to the west – separated by the Rhine – and Düsseldorf to the north.
The town covers an area of 2,305 hectares, and its altitude ranges between 35 and 45 meters above sea level. From north to south, it extends about 7.5 km, from west to east about 6 km. The Lower Rhine terrace, whose subsoil consists of pure sand and gravel soils overlaid by fertile alluvial clay, merges eastwards into the Bergisches Land region. Its heights reach more than 350 meters above sea level. The town area belongs to the "Cologne Bay" climate zone and has moderately warm summers and mild winters.
The town has just over 43,000 inhabitants (including secondary residences), about two thirds of whom live in the Monheim district and one third in the Baumberg district.