Raoul Duke
The protagonist of the narrative and a stand-in for the author, Hunter S. Thompson. Duke is a heavy drinker and drug user. As a result, he is prone to erratic and outrageous behavior, but he does occasionally display compassion for the people around him.
Duke's attorney
Raoul Duke's attorney is not explicitly named in the text, though he uses "Dr. Gonzo" to check into a hotel and to sign his telegram. An overweight Samoan, he is one of Duke's best friends. Like the narrator, he uses drugs extensively. He is slightly more impulsive and prone to aggression than Duke; he also shows little regard for the people around him.
Lacerda
The photographer assigned to photograph the race with Duke. He is committed to his assignment - a marked contrast to Duke, who has other plans.
The hitchhiker
A young man who requests a ride from Duke and his attorney on the way to Las Vegas. He is frightened by their erratic behavior and leaves the car the first chance he gets.
Joe
Duke and Lacerda's driver, who has been assigned to help them document the race. His real name is Steve.
Dr. –––
An LSD advocate who used to live near Duke in San Francisco.
Mr. Heem
The manager at the Mint Hotel.
Lucy
A young woman from Montana whom Duke's attorney picks up on his flight to Las Vegas. She paints portraits of Barbra Streisand as a hobby, and has come to Vegas to show Streisand her work.
Patrick Healy
The executive director of the National District Attorneys’ Association.
Dr. E.R. Bloomquist
A medical professor from the University of Southern California and the keynote speaker at the drug conference. Duke scathingly criticizes Bloomquist’s speech and his writings on marijuana.
Lou
The cook at the restaurant in Boulder City.
Alice
A maid at the Flamingo Hotel who walks in on Duke's attorney while he is naked and vomiting in the closet. He subsequently attacks her, but Duke and his attorney defuse the situation by pretending to be cops and recruiting her as a confidential informant.
Bruce Innes
A musician and a friend of Duke's.
The Astronaut
An unnamed retired astronaut who gets into a drunken argument with Bruce Innes in Aspen, several months after the main narrative ends.