A Malthusian catastrophe is a situation in which a society returns to a subsistence level of existence as a result of overtaxing its available agricultural resources. There are numerous alternate names for this situation; some people refer to it as a Malthusian crisis, trap, or disaster, for example. Some theorists also believe that every society has a Malthusian limit, a population tipping point which will spark such a crisis. The concept of a Malthusian check on population levels has been debated extensively, especially in the 20th century, with the rapidly growing human population raising concerns for some people.

The idea of a Malthusian catastrophe was put forward by Thomas Malthus in An Essay on the Principle of Population in 1798. Malthus pointed out that human populations tend to grow exponentially, while the capabilities of agricultural resources tend to grow arithmetically. Using these patterns, Malthus predicted that at a certain point, the demands of a human population would outstrip agricultural ability. This, in turn, would trigger radical social changes, including population decline and, according to Malthus, a state of misery.

The history of several cultures does seem to suggest that a Malthusian catastrophe may be a very real threat; societies such as Easter Island did utilize all of their available resources and collapse, for example. Overpopulation is also clearly linked to disease epidemics, starvation, and social unrest. Some people believe, however, that Malthus oversimplified the matter, and that there may be ways to address a growing population without causing misery. Others suggest that the growing disparity between First and Third world nations indicates that a Malthusian catastrophe may already be occurring.

Concerns about global population growth have led to numerous studies on the world's population, including estimates of the global population from periods before records were kept. These estimates do show an exponential rate of growth, but in the 20th century, this growth rate became hypoerexponential, meaning that it increased even more radically. However, in the developed world, populations are actually on the decline; this means that the growth is concentrated in developing countries, which could lead to serious problems in the future.

Developed nations also use a disproportionate amount of resources, which puts even more pressure on developing countries. If a Malthusian catastrophe does emerge, people who support this theory of population predict that it will appear in developing nations. Some parts of the Third World are already struggling with famine, disease, and violence, which means that this tipping point could be close at hand.