The most densely populated European countries are Monaco (population 38,000; population density 18,700/km2) and Vatican City (with population of approximately 1,000, giving it the population density of 2,300/km2). However, the most densely populated European country that is not a city-state is Malta, with a population of approximately 450,000 and population density 1,400/km2.
On the other hand, the least densely populated European country is Iceland (population 330,000; population density just around 3.2 people per square kilometre). To understand the magnitude of differences, take a look at the following infographic, which shows the two countries side by side: