What real-life Massachusetts town inspired the fictional Innsmouth?

The real Massachusetts town that inspired fictional Innsmouth is Newburyport. Lovecraft visited Newburyport in 1923 and again in 1931, and he drew on its old architecture, coastal setting, and atmosphere of faded maritime prosperity when creating Innsmouth.

In The Shadow over Innsmouth, the narrator visits Newburyport before taking a bus to the decaying fictional seaport. That detail makes the connection unusually direct: Newburyport is not merely a similar town but an actual neighboring location within the story's geography.

Lovecraft described Innsmouth as a distorted version of Newburyport. He transformed recognizable New England features—weathered buildings, colonial history, salt marshes, and a declining port economy—into a setting of secrecy, family corruption, and supernatural horror. The fictional town's history also includes Obed Marsh, the Esoteric Order of Dagon, and the Deep Ones.

Innsmouth itself is not a real Massachusetts municipality. It belongs to Lovecraft's invented Miskatonic region, alongside Arkham, Dunwich, and Kingsport. Newburyport is therefore the best canonical answer, while Salem and Gloucester are only broader atmospheric associations.