Bucharest (UK: /ˌbuːkəˈrɛst/ ^ⓘ BOO-kə-REST, US: /ˈbuːkərɛst/ -⁠rest; Romanian: București [bukuˈreʃtʲ] ^ⓘ) is the capital and largest city of Romania. The metropolis stands on the River Dâmbovița in south-eastern Romania. Its population is officially estimated at 1.71 million residents within a greater metropolitan area of 2.31 million residents, which makes Bucharest the 8th most-populous city by population within city limits in the European Union. The city area measures 240 km² (93 sq mi), while the metropolitan area covers 1,811 km² (699 sq mi). The city proper is administratively known as the "Municipality of Bucharest" (Romanian: Municipiul București), and has the same administrative level as that of a national county, being further subdivided into six sectors, each governed by a local mayor. Bucharest is a major cultural, political and economic hub, the country's seat of government, and the capital of the Muntenia region.

Bucharest was first mentioned in documents in 1459. The city became the capital in 1862 and is the centre of Romanian media, culture, and art. Its architecture is a mix of historical (mostly Eclectic, but also Neoclassical and Art Nouveau), interbellum (Bauhaus, Art Deco, and Romanian Revival architecture), socialist era, and modern. In the period between the two World Wars, the city's elegant architecture and the sophistication of its elite earned Bucharest the nicknames of Little Paris, or Paris of the East. Although buildings and districts in the historic city centre were heavily damaged or destroyed by war, earthquakes, and even Nicolae Ceaușescu's program of systematization, many survived and have been renovated. In recent years, the city has been experiencing an economic and cultural boom. It is one of the fastest-growing high-tech cities in Europe. In 2016, the historical city centre was listed as "endangered" by the World Monuments Watch.

Bucharest is by far the most populous city of Romania, having reached one million inhabitants in the 1940s. In 2017, Bucharest was the European city with the highest growth of tourists who stay over night, according to the Mastercard Global Index of Urban Destinations. In 2018 and 2019, Bucharest ranked as the European destination with the highest potential for development according to the same study.

Economically, Bucharest is the most prosperous city in Romania and the richest capital and city in the region, having surpassed Budapest since 2017. The city has a number of large convention facilities, educational institutes, cultural venues, traditional "shopping arcades" and recreational areas. Bucharest is within, and surrounded by, the Ilfov County.

The Romanian name București has an unverified origin. Tradition connects the founding of Bucharest with the name of Bucur, who was a prince, an outlaw, a fisherman, a shepherd or a hunter, according to different legends. In Romanian, the word stem bucurie means 'joy' ('happiness'), hence the city Bucharest means 'city of joy'.

Other etymologies are given by early scholars, including the one of an Ottoman traveller, Evliya Çelebi, who claimed that Bucharest was named after a certain "Abu-Kariș", from the tribe of "Bani-Kureiș". In 1781, Austrian historian Franz Sulzer claimed that it was related to bucurie (joy), bucuros (joyful), or a se bucura (to be joyful), while an early 19th-century book published in Vienna assumed its name to be derived from "Bukovie", a beech forest. In English, the city's name was formerly rendered as Bukarest. A native or resident of Bucharest is called a "Bucharester" (Romanian: bucureștean).

Bucharest's history alternated periods of development and decline from the early settlements in antiquity until its consolidation as the national capital of Romania late in the 19th century. First mentioned as the 'Citadel of București' in 1459, it became the residence of the ruler of Wallachia, Voivode Vlad the Impaler.

The Old Princely Court (Curtea Veche) was erected by Mircea Ciobanul in the mid-16th century. Under subsequent rulers, Bucharest was established as the summer residence of the royal court. During the years to come, it competed with Târgoviște on the status of capital city after an increase in the importance of Southern Muntenia brought about by demands of the suzerain power – the Ottoman Empire.