A lobby is a room in a building used for entry from the outside. Sometimes referred to as a foyer, reception area or an entrance hall, it often is a large, room or complex of rooms (in a theatre, opera house, concert hall, showroom, cinema, etc.) adjacent to the auditorium. It is a repose area for spectators and place of venues, especially used before performance and during intermissions but also as a place of celebrations or festivities after performance.

Since the mid-1980s, there has been a growing trend to think of lobbies as more than just ways to get from the door to the elevator but instead as social spaces and places of commerce.^[1][2] Some research has even been done to develop scales to measure lobby atmosphere to improve hotel lobby design.^[3] Many office buildings, hotels and skyscrapers go to great lengths to decorate their lobbies to create the right impression and convey an image.^[4][5][6]

Supertall skyscrapers can often have one or more of what is known as a sky lobby, an intermediate floor where people can change from an express elevator that stops only at the sky lobby to a local elevator which stops at every floor within a segment of the building.