F. Scott Fitzgerald's The Great Gatsby is set in New York city and Long Island, where there are two areas known as East Egg and West Egg. East Egg is the more exclusive section, and West Egg is where the nouveau riche live. The narrator describes this area as "one of the strangest communities in North America."

• The novel is narrated by Nick Carraway, whose second cousin once removed is Daisy Buchanan, lives in a cottage in West Egg that is next door to Jay Gatsby's mansion, modeled after a French hôtel de ville, a structure that is architecturally termed Renaissance Revival, a very ornate and elaborate style.
• Across the bay are the mansion and stables of Daisy and Tom Buchanan in East Egg. Nick Carraway has been acquainted with Tom while in college at Yale and finds him rather brutish and extremely rich.
• Tom carries on an affair with Myrtle Wilson, who lives in the Valley of Ashes, an area between Long Island and New York City. Myrtle is married to George Wilson, who has a dilapidated auto-shop. George trusts Tom Buchanan and believes that Tom is interested in transacting business with him. Myrtle, also, trusts Tom to carry her out of her grey existence. But Tom does not care about either of them.
• Jordan Baker is a friend of Daisy's from Louisville, Kentucky. She lives in New York, specifically Manhattan, in her aunt's apartment. Jordan is cynical and jaded, joking that she prefers large parties because they are so private. She dates Nick, but is insincere with him.
• Klipspringer - This man is a freeloader in Gatsby's house, living off his host. Soon after Gatsby dies, Klipspringer disappears and does not attend the funeral. He later phones and asks about a pair of tennis shoes that he has left in Gatsby's house.
• Meyer Wolfschiem lives in New York. He is a mobster who helped Gatsby make money in bootlegging. While he continues his relations with Gatsby, he is afraid to show up at Gatsby's funeral, worried that he might be arrested. 

Tom and Daisy Buchanan are married and live in East Egg. Gatsby and Nick live in West Egg. Gatsby lives in a mansion; Nick lives in a small cottage next door. George and Myrtle Wilson are married and live above a gas station in the Valley of the Ashes.

Nick went to college with Tom, is related to Daisy, and lives next door to Gatsby. Nick met Myrtle through Tom Buchanan, her lover, but she plays no role in his life.

Gatsby becomes Nick's friend. He has renewed the affair with Daisy that began five years earlier.

George runs the gas station where Tom buys his gas. Myrtle and Tom are having an affair.

Jordan Baker is Daisy's friend from years before in Louisville. She is living in New York and visiting Tom and Daisy on weekends. She and Nick start seeing each other, but Nick breaks it off.

See the eNotes links below for a good summary of the novel and information about the setting and the characters.