What is the name of the town on Long Island that inspired West Egg?

The Long Island town that inspired West Egg is Great Neck, particularly the Kings Point area.

F. Scott Fitzgerald lived in Great Neck from 1922 to 1924, when he was developing The Great Gatsby. The town's mixture of established wealth and recently acquired fortunes helped him shape the novel's contrast between West Egg and East Egg. In the fictional geography, West Egg represents “new money,” while East Egg represents inherited “old money.”

Great Neck also influenced the atmosphere of the novel. Fitzgerald encountered lavish parties, ambitious social climbers, and the uneasy cultural divide between established families and newly rich residents. Those observations became part of the world surrounding Gatsby, Nick Carraway, Daisy Buchanan, and Tom Buchanan.

The real-life model for East Egg is generally associated with nearby Port Washington, especially Sands Point. That distinction explains why Southampton and East Hampton are tempting but incorrect choices: both are famous Long Island communities, yet they are not the principal locations linked to Fitzgerald's fictional eggs.

West Egg is not an exact one-to-one map of Great Neck. Fitzgerald combined several places, homes, and social impressions, with Kings Point usually identified as the most specific local counterpart.