Officially known as the Principality of Monaco, Monaco is a sovereign city-state and microstate on the French Riviera, a few kilometers west of the Italian region of Liguria, on the Mediterranean Sea in Western Europe. France stretches to its north, east, and west. The principality has 38,682 residents, 9,486 of whom are Monégasques. It is widely acknowledged as one of the wealthiest and most expensive places in the world. French is the principality's official language. Additionally, many residents speak and understand Italian, English, and Monégasque, a Ligurian dialect.

It is the second-smallest sovereign state in the world, after Vatican City, with an area of 2.1 km2 (0.81 sq mi). It is the most populous sovereign state in the world, with 19,009 people per km2 (49,230 people per sq mi). The land border of Monaco is 5.47 kilometers (3.40 miles) long, and its coastline is the shortest in the world, measuring approximately 3.83 kilometers (2.38 miles); its width ranges from 1,700 meters (5,577 feet) to 349 meters (1,145 feet). Chemin des Révoires, a narrow path in the Les Révoires ward on the slopes of Mont Agel, is the state's highest point at 161 meters (528 feet) above sea level. The border with Italy is approximately 15.3 miles away from the principality. With 5,443 people as of 2008, Larvotto/Bas Moulins is its most populous ward. Monaco's land area has grown by 20% thanks to land reclamation. It only covered 1.974 km2 (0.762 sq mi) in 2005.