The population figures show the enormous growth Monheim am Rhein has experienced since it became a town in 1960.
- From 1960 to 1965, the number of inhabitants rose from 13,692 to 21,698 (as counted at the end of each year).
- In 1970, there were already 39,128 and in 1975 – after the Hitdorf district had been incorporated into Leverkusen - 37,326 residents in the town.
- In 1980, there were 40,559 inhabitants, and in 1990, 42,824.
- At the end of 2010, 43,702 people lived within the city limits.
About two thirds of the population live in the Monheim district and one third in the Baumberg district.
Due to the current legal situation and the lawsuit filed by the City of Monheim am Rhein against the population figure officially determined by the 2011 census, only the city's own data, based on the population registration system, are used here.
For comparison: The number of inhabitants (with their primary residence here) as officially decided by the 2011 census on May 9, 2011, was 40,280. As of the same date, however, the municipal registration system recorded 42,170 inhabitants who had their primary residence in the town.
Total population
| | In total | Male | Female |
| Inhabitants | 44,942 | 21,909 | 23,033 |
| Inhabitants with their primary residency here | 43,956 | 21,404 | 22,552 |
| Inhabitants with their secondary residence here | 986 | 505 | 481 |
Data from the City of Monheim am Rhein, reference date: December 31, 2021
