A spaceport was a location where spaceships took off and landed.
Some of the spaceports visited by the Doctor and their companions were Elvis the King Spaceport on New Memphis (PROSE: Judgement of the Judoon), Tantane Spaceport on Tantane (AUDIO: Spaceport Fear), Amber Station (PROSE: Briefly Noted), Dalek City (PROSE: War of the Daleks), Cornucopia (COMIC: The Cornucopia Caper, Hunters of the Burning Stone), as well as those on Ekthelios (COMIC: Attack of the GateBots!) and Hera. (PROSE: The Squire's Crystal)
In an alternate timeline, the First Doctor's companion Steven Taylor found work in the spaceport in Kiria City, the capital of Urbinia. It became the central point of the city's evacuation during the invasion by the Daleks. (AUDIO: Daughter of the Gods)