Overcrowding or crowding is the condition where more people are located within a given space than is considered tolerable from a safety and health perspective. Safety and health perspectives depend on current environments and on local cultural norms. Overcrowding may arise temporarily or regularly, in the home, in public spaces or on public transport. Overcrowding in the home can cause particular concern, since the home is an individual's place of shelter.

Effects on quality of life due to crowding may include increased physical contact, lack of sleep, lack of privacy and poor hygiene practices. While population density offers an objective measure of the number of people living per unit area, overcrowding refers to people's psychological response to density. However, definitions of crowding used in statistical reporting and for administrative purposes depend on density measures and do not usually incorporate people's perceptions of crowding.

It is important to avoid over crowding in today's times as they lead to health problems. Some individuals are also not comfortable in crowded areas. Certain places are prone to be crowded.