Monaco, officially the Principality of Monaco, is a tiny, sovereign city-state on the French Riviera, renowned as the world's second smallest and most densely populated nation, spanning just 2.08 km² with a population of 38,423. Ruled by the House of Grimaldi since 1297, it operates as a semi-constitutional monarchy under Prince Albert II, with its sovereignty formally recognized by the 1861 Franco-Monégasque Treaty and full UN membership gained in 1993.

This microstate is celebrated as one of the world's wealthiest and most expensive places, serving as a prominent tax haven and banking hub. Its economic boom in the late 19th century was largely spurred by the opening of the Monte Carlo Casino and a vital rail connection to Paris. Monaco's mild climate, scenic beauty, and gambling facilities attract the ultra-rich, establishing it as a premier tourist destination and host of prestigious events like the annual Monaco Grand Prix. Despite its independence, France handles its defence, and while Monaco uses the Euro, it was recently placed under increased monitoring by the Financial Action Task Force (FATF) in June 2024 to combat money laundering.