Monte Carlo (French: Monte-Carlo or colloquially Monte-Carl, Monégasque: Monte-Carlu) officially refers to an administrative area of the Principality of Monaco, specifically the ward of Monte Carlo/Spélugues, where the Monte Carlo Casino is located. Informally the name also refers to a larger district, the Monte Carlo Quarter (corresponding to the former municipality of Monte Carlo), which besides Monte Carlo/Spélugues also includes the wards of La Rousse/Saint Roman, Larvotto/Bas Moulins, and Saint Michel. The permanent population of the ward of Monte Carlo is about 3,500, while that of the quarter is about 15,000. Monaco has four traditional quarters. From west to east they are: Fontvieille (the newest), Monaco-Ville (the oldest), La Condamine, and Monte Carlo.

Monte Carlo (literally "Mount Charles") is situated on a prominent escarpment at the base of the Maritime Alps along the French Riviera. Near the western end of the quarter is the world-famous Place du Casino, the gambling center which has made Monte Carlo "an international byword for the extravagant display and reckless dispersal of wealth". It is also the location of the Hôtel de Paris, the Café de Paris, and the Salle Garnier (the casino theatre which is the home of the Opéra de Monte-Carlo). The eastern part of the quarter includes the community of Larvotto with Monaco's only public beach, as well as its new convention center (the Grimaldi Forum), and the Monte-Carlo Bay Hotel & Resort. At its eastern border one crosses into the French town of Beausoleil (sometimes referred to as Monte-Carlo-Supérieur), and just 5 miles (8 km) further east is the western border of Italy.