What is the most densely populated country in the world?

Monaco is the most densely populated country in the world. This tiny sovereign principality on the French Riviera packs tens of thousands of residents into roughly 2 square kilometres, producing a population density far above that of any other country.

Monaco’s geography explains the ranking. It is bordered by France on three sides and the Mediterranean Sea on the fourth, leaving very little land for expansion. Extensive construction, including land reclamation projects such as the Le Portier district, has allowed the principality to add usable space without changing its basic character as a compact city-state.

Vatican City is smaller in both area and population, but its population density is lower. Hong Kong and Singapore are also exceptionally dense urban places, yet Hong Kong is a special administrative region rather than a sovereign country, while Singapore is a separate country with substantially more land. Rankings can shift slightly as populations and boundaries change, but Monaco remains the standard answer.