Most of Mumbai's inhabitants rely on public transport to travel to and from their workplace due to the lack of car parking spaces, traffic bottlenecks, and generally poor road conditions. The city is the headquarters of two rail divisions – the Central Railway (CR) (headquartered at Chatrapati Shivaji Terminus, formerly known as Victoria Terminus), and the Western Railway (WR), headquartered near Churchgate). The backbone of the city's transport, the Mumbai Suburban Railway, is composed of three separate networks running the length of the city, in a north-south direction. The Western Railway runs along the western region of the city, while the Central Railway covers most of the central and northeast parts of the metropolis. Both lines extend into the exurbs, each covering a total one-way length of around 125 km. The Harbour Line is a sub-division of the Central Railway, covering a distance of 54 km along the south-eastern section of the city, near the docks, and extending into Navi Mumbai (New Bombay). Mumbai is well connected by the Indian Railways to most parts of India.

Public buses run by the BEST (an autonomous body under the BMC) cover almost all parts of the metropolis, as well as parts of Navi Mumbai and Thane. Buses are used for commuting short to medium distances, while train fares are more economical for long distance commutes. The BEST fleet consists of single-decker, double-decker and air-conditioned.

Black and yellow-metered taxis, accommodating up to four passengers, cover most of the metropolis. Auto rickshaws, allowed to operate only in the suburban areas, are the main form of hired transport here. These three-wheeled vehicles can accommodate up to three passengers.

Mumbai's Chatrapati Shivaji International Airport (formerly, Sahar International Airport) is the busiest airport in India, and caters to cargo and international flights while Santacruz Airport caters to domestic flights. The nearby Juhu aerodrome was India's first airport, and now hosts a flying club and a heliport.

With its unique topography, Mumbai has one of the best natural harbours in the world, handling 50% of the country's passenger traffic, and much of India's cargo. It is also an important base for the Indian Navy.