Johannesburg lies in Gauteng , the wealthiest province in South Africa and forms part of the City of Johannesburg municipality. Locals have nicknamed the most populous city in South Africa “Joburg”, “Jozi” and “eGoli”.

The City of Johannesburg is one of the largest metropolitan areas in the world with a population of just over three million people. Johannesburg, which was founded on the mineral-rich Witwatersrand hills, is the site of a large-scale gold trade.

The city is serviced by OR Tambo International Airport (formerly Johannesburg International Airport), the largest and busiest airport in Africa and a gateway for international air travel to and from the rest of southern Africa.

Johannesburg produces 16 % of South Africa's gross domestic product, and accounts for 40% of Gauteng's economic activity. While gold mining no longer takes place within the city limits, most mining companies have their headquarters in Johannesburg. A variety of manufacturing industries also operate in the city. Many banking and commercial companies are also located in Johannesburg and so is Africa's largest stock exchange, the JSE Securities Exchange.

The City of Johannesburg’s land area of 1 644 km² is large when compared with other cities. It also encompasses the townships of Soweto to the south west and Orange Farm and Alexandra to the north.