Mumbai, also known as Bombay is the capital of the Indian state of Maharashtra. It is the most populous city in India, and the most populous city in the world, with a population of approximately 14 million. Along with the neighbouring urban areas, including the cities of Navi Mumbai and Thane, it is one of the most populous urban regions in the world. Mumbai lies on the west coast of India and has a deep natural harbour. As of 2009, Mumbai was named an Alpha world city. Mumbai is also the richest city in India, and has the highest GDP of any city in South or Central Asia.

The seven islands that came to constitute Mumbai were home to communities of fishing colonies. For centuries, the islands came under the control of successive indigenous empires before being ceded to the Portuguese and subsequently to the British East India Company. During the mid-18th century, Bombay was reshaped by the British with large-scale civil engineering projects, and emerged as a significant trading town. Economic and educational development characterised the city during the 19th century. It became a strong base for the Indian independence movement during the early 20th century. When India became independent in 1947, the city was incorporated into Bombay State. In 1960, following the Samyukta Maharashtra movement, a new state of Maharashtra was created with Bombay as capital. It was renamed Mumbai in 1996.

Mumbai is the commercial and entertainment capital of India, generating 5% of India's GDP, and accounting for 25% of industrial output, 70% of maritime trade in India (Mumbai Port & JNPT), and 70% of capital transactions to India's economy. Mumbai is home to important financial institutions such as the Reserve Bank of India, the Bombay Stock Exchange, the National Stock Exchange of India and the corporate headquarters of numerous Indian companies and multinational corporations. It houses India's premier nuclear institutes like BARC, NPCL, IREL, TIFR, AERB, AECI, and the Department of Atomic Energy. The city also houses India's Hindi film and television industry, known as Bollywood. Mumbai's business opportunities, as well as its potential to offer a higher standard of living, attract migrants from all over India and, in turn, make the city a potpourri of many communities and cultures.