Public transport, public transportation, public transit or mass transit comprise all transport systems in which the passengers do not travel in their own vehicles. While the above terms are generally taken to include rail and bus services, wider definitions might include scheduled airline services, ferries, taxicab services etc. — any system that transports members of the general public. A further restriction that is sometimes applied is that transit should occur in continuously shared vehicles, which would exclude taxis that are not shared-ride taxis.

The term public transport is preferred in the British Isles and most Commonwealth countries, whereas public transportation, public transit and mass transit are used most often in North America. The term transit is less likely to include long-distance forms of public transportation, such as long-distance or commuter railroads, inter-city buses, or intercity railways.

Public transport is usually regulated as a common carrier and is usually configured to provide scheduled service on fixed routes on a non-reservation basis, although share taxis provide an ad-hoc form of flexible public transport, and demand responsive transport provides a pre-bookable form of public shared transport. Taxicabs and other vehicles for hire are generally fully flexible.

The majority of transit passengers are traveling within a local area or region between their homes and places of employment, shopping, or schools.