Jay Gatsby: The protagonist who gives his name to the story. Gatsby is a newly wealthy Midwesterner-turned-Easterner who orders his life around one desire: to be reunited with Daisy Buchanan, the love he lost five years earlier. His quest for the American dream leads him from poverty to wealth, into the arms of his beloved and, eventually, to death.
Nick Carraway: The story's narrator. Nick rents the small house next to Gatsby's mansion in West Egg and, over the course of events, helps Gatsby reunite with Daisy (who happens to be Nick's cousin). Nick's Midwestern sensibility finds the East an unsettling place, and he becomes disillusioned with how wealthy socialites like the Buchanans lead their lives.
Daisy Buchanan: Beautiful and mesmerizing, Daisy is the apex of sociability. Her privileged upbringing in Louisville has conditioned her to a particular lifestyle, which Tom, her husband, is able to provide her. She enraptures men, especially Gatsby, with her diaphanous nature and sultry voice. She is the object of Gatsby's desire, for good or ill, and represents women of an elite social class.
Tom Buchanan: Daisy's hulking brute of a husband. Tom comes from an old, wealthy Chicago family and takes pride in his rough ways. He commands attention through his boisterous and outspoken (even racist) behavior. He leads a life of luxury in East Egg, playing polo, riding horses, and driving fast cars. He is proud of his affairs and has had many since his marriage. Myrtle Wilson is merely the woman of the moment for Tom.
Jordan Baker: Professional golfer of questionable integrity. Friend of Daisy's who, like Daisy, represents women of a particular class. Jordan is the young, single woman of wealth, admired by men wherever she goes. She dates Nick casually, but seems offended when he is the first man not to fall for her charms. Although she is savvy, she comes off as somewhat shallow in her approach to life.
Myrtle Wilson: Married lover of Tom Buchanan. Myrtle serves as a representative of the lower class. Through her affair with Tom she gains entrée into the world of the elite, and the change in her personality is remarkable. She conducts a secret life with Tom, wherein she exhibits all the power and dominance she finds lacking in her everyday life. She eventually suffers a tragic end at the hands of her lover's wife.
George Wilson: Myrtle's unassuming husband. He runs a garage and gas station in the valley of ashes and seems trapped by his position in life. Eventually, he finds out about his wife's double life and his response to it helps drive her to her death. Distraught at what happens, Wilson becomes Fitzgerald's way of expressing the despair prevalent in the seemingly trapped lower-middle class.
Catherine: Sister of Myrtle Wilson who is aware of her sister's secret life and willing to partake of its benefits.
Meyer Wolfshiem: We don't know a lot about Meyer Wolfsheim and we're not supposed to. Beyond the fact that he's a business associate and a friend of Gatsby's, all we know is that he's an inhabitant of New York's seedy underworld and a dead ringer for real-life Arnold Rothstein: the man who really did fix the 1919 World Series, one of Meyer Wolfsheim's impressive accomplishments.
Although Wolfsheim remains a mystery, we end up learning quite a lot about other characters through him. First of all, his business "goneggtions" with Gatsby shine a rather dubious light upon the latter's dealings. Even though Gatsby wants everyone to believe that he's the real deal, we begin to wonder how he really earned that fortune.
Wolfsheim also reveals some rather unfortunate things about one of our other main characters, Nick, like that he's innately judgmental. Nick is clearly intrigued by the guy, but he also acts like he's got a bad taste in his mouth around him. This shows us the bias against the foreign "Other" (Wolfsheim is Jewish) prevalent in so-called "respectable" society of the time. The same kind of bias that makes Tom declare that the "Nordic race" is being submerged, and the same kind of bias that led just two decades later to the Holocaust.
Michaelis: George Wilson's restaurateur neighbor who comforts Wilson after Myrtle is killed. One of the few charitable people to be found in the novel.
Dan Cody: Worldly mentor of Jay Gatsby. Cody took Gatsby under his wing when Gatsby was a young man and taught him much about living adventurously and pursuing dreams.
Henry C. Gatz: Father of Jay Gatsby. Comes from the Midwest to bury his son. Gatz serves as a very tangible reminder of Gatsby's humble heritage and roots.