The country with the highest population density is Monaco. This small city-state located on the French Riviera is known for its luxurious lifestyle and immense wealth concentrated within a limited area. With a population of around 39,000 people residing in just about 2 square kilometers, Monaco's population density is extraordinarily high. The city-state’s economy is primarily driven by tourism, finance, and the gaming industry. Its unique combination of affluence and small geographical size makes it a notable example of high population density.