Kingsport is based on Marblehead, Massachusetts, a town bordering Salem. Lovecraft created Kingsport before he saw its real-life model. When Lovecraft visited Marblehead in 1922, he became enamored of the town and wrote with much feeling in 1929 concerning his experiences there. Lovecraft wrote of seeing the snow-covered town at sunset and of experiencing his "first stupid glance of [Marblehead's] huddled and [archaic] roofs". He also remarked that "that instant — about 4:05 to 4:10 pm., Dec. 17, 1922 — [was] the most powerful single emotional climax during my nearly forty years of existence." 
In Lovecraft's fiction, Kingsport is located in the United States to the southeast of (the fictitious) Arkham and corresponds geographically with the town of Marblehead, MA. Lovecraft's alter ego Randolph Carter grew up and lived here.
According to later writers, the town was founded in 1639 by colonists from southern England and the Channel Islands. It soon became a seaport and center for shipbuilding. Influenced by the Salem witch trials, the town hanged four alleged witches in 1692. During the American Revolutionary War, the port was briefly blockaded by the British when the town's merchants turned to privateering against the British fleet. In the 19th century, sea trade dwindled and the town turned to fishing as the main industry. Kingsport's economy continued to dwindle into the 20th century and today relies primarily on tourism for income.
- "The Terrible Old Man" (1921): The eponymous resident of Kingsport lives on Water Street near the sea.
- "The Festival" (1923): The unnamed narrator is summoned to Kingsport to participate in a strange ceremony held by his distant relatives.
- The Dream-Quest of Unknown Kadath (1926): Nyarlathotep expresses admiration for Kingsport's "antediluvian" architecture and marvelous seacoast. A moving conclusion to the novella takes place here.
- "The Silver Key" (1926): Randolph Carter has traveled back in time to the 1880s when he glimpses Kingsport's "old Congregational steeple on Central Hill" and realizes that the old church had been torn down to build Congregational Hospital.
- "The Strange High House in the Mist" (1926): College teacher Thomas Olney meets the lone occupant of the eponymous dwelling, which lies atop a high cliff on Kingsport's coast.
- The Case of Charles Dexter Ward (1927): John Merritt mentions Kingsport and the strange rites he had heard were performed there.
- "The Thing on the Doorstep" (1933): A teenaged Asenath Waite attended an all-girls school, the Hall School, in Kingsport.
In work by other writers
The town was mentioned in Robert Bloch's short story "Notebook Found in a Deserted House" and The Illuminatus! Trilogy by Robert Shea and Robert Anton Wilson, and appeared in An Evil Guest by Gene Wolfe. The original draft of Ramsey Campbell's "The Church in High Street" was set in Kingsport, before August Derleth persuaded Campbell to rewrite the story in a British setting; the town Temphill.
- Kingsport appears in the tabletop games Call of Cthulhu, Kingsport Festival, and in an expansion to Arkham Horror. The Call of Cthulhu sourcebook Kingsport: The City in the Mists provides maps, history and other information for roleplayers and game masters.
- Kingsport is one of four towns on the board in the tabletop game Pandemic: Reign of Cthulhu (2016), a variant of Pandemic (2008).
- Pearsall, Anthony B. (2005). "Kingsport". The Lovecraft Lexicon (1st ed.). Tempe, AZ: New Falcon Pub. p. 247. ISBN 1-56184-129-3.
- Harms, Daniel (1998). "Kingsport". The Encyclopedia Cthulhiana (2nd ed.). Oakland, CA: Chaosium. pp. 166–167. ISBN 1-56882-119-0.