Heritage streetcars or heritage trams are a development of the heritage railways that are becoming popular across the world. As with modern streetcar systems, the vehicles are referred to as trams or tramcars in the United Kingdom, Australasia and certain other places (with tramway being the line or system), but as streetcars or trolleys in North America. The last two terms are often used interchangeably in the United States, with trolley being preferred in the eastern U.S. and streetcar in Canada and the western U.S.

There are several kinds of heritage streetcar lines. They can use original vintage vehicles or replicas of historic vehicles. They can be either newly installed lines (created in modern times, 1970s or later) or be surviving older streetcar lines/tramways which have retained use of historic streetcars/trams for all or most of their scheduled service. Several new heritage streetcar lines have been opened since the 1970s, particularly in the United States, and some are stand-alone lines while others make use of a section of a modern light rail system. Some use all-new construction while others make use of an existing, usually disused, freight railway, by installing overhead wires and passenger stops. However, in all cases they are actual rail lines and not simply buses made to resemble a streetcar, although the latter are often referred to—inaccurately—as "trolleys" in the towns where they operate (see tourist trolley).