Wade is an impoverished teenager living in an overcrowded trailer park in Oklahoma. To escape the bleak reality of his surroundings, he devotes his free time to the OASIS, an expansive virtual reality universe. Operating under the avatar Parzival, Wade is a dedicated egg hunter who studies 1980s pop culture meticulously to find the hidden prize left by the system's late creator. He attends school in the virtual world, operating a low-level avatar because he lacks the funds to travel off-world. He utilizes his encyclopedic knowledge of arcade games, movies, and music to advance in the global contest.

Operating under the avatar Art3mis, this character is a highly respected participant in the Easter egg hunt. She maintains a popular public blog that chronicles her progress and shares her extensive knowledge of 1980s pop culture. Fiercely independent and protective of her real-world identity, she frequently prefers text-based communication to carefully consider her words. She aims to use the contest's massive prize money to solve global issues and save humanity from ecological and economic collapse.

Known primarily by the avatar Aech, this character is a top-ranked virtual combatant and Wade's best friend. Aech runs "the Basement," a highly exclusive virtual hangout for elite players, where friends test each other's trivia knowledge and debate classic pop culture. Aech is a formidable competitor in the hunt who maintains strict secrecy regarding her real-world identity while dominating the digital leaderboard. She frequently plays arcade games like Joust to settle disputes.

Nolan Sorrento is the chief of operations for Innovative Online Industries (IOI), a powerful communications corporation attempting a hostile takeover of the virtual world. He commands the "Sixers," an army of corporate employees tasked with winning the contest at any cost. Calculating and ruthless, Sorrento views the virtual universe purely as a resource to be monetized and tightly controlled, showing zero regard for the original spirit of the game or the lives of individual players.

Ogden Morrow is the former business partner of the virtual world's creator and co-founder of Gregarious Simulation Systems. He handled the business and public relations side of the company before retiring to a quiet life in Oregon. Operating under the avatar Og, he retains supreme access privileges within the digital universe but publicly chooses to observe the contest from afar to protect its integrity. He acts as a quiet guardian of the creator's original vision.

The eccentric, socially inept billionaire creator of the virtual universe, James Halliday passes away and leaves his entire fortune to whoever can solve a series of fiendishly difficult pop culture puzzles. Operating under the wizard avatar Anorak, his obsessive love for the 1980s dictates the entire culture of the global digital system he built. His posthumous contest changes the global economy and culture permanently, sparking a worldwide obsession with the media of his youth.

Operating in the OASIS under the avatar Shoto, he is a dedicated competitor who works closely with his virtual partner, Daito. He wears traditional samurai armor in the digital world and relies on strict teamwork to progress through the challenges of the hunt. He strictly limits his interactions with other players, preferring to rely entirely on shared cultural knowledge with his partner to solve the creator's riddles.

Known in the virtual world as Daito, he forms a tight-knit duo with Shoto. Like his partner, his avatar wears traditional samurai armor, and he is highly protective of their progress in the global contest. He prefers to maintain strict isolation from others, frequently rejecting the idea of forming larger groups to solve the contest's puzzles. He acts as the older, more cautious half of the partnership.

Aunt Alice is Wade's guardian in the real world following the death of his mother. Struggling with drug addiction and extreme poverty, she only houses Wade to collect extra government food vouchers. She lives in a cramped trailer in the stacks and subjects Wade to neglect while tolerating threats from her violent boyfriend.

I-R0k is an arrogant participant in the global contest who occasionally frequents Aech's private chat room. He frequently attempts to prove his superiority by challenging others to trivia battles, though his actual knowledge and skills often fall short of the truly elite players. He uses intimidation and blackmail to try and advance his own standing.

Kira Morrow is Ogden Morrow's high school sweetheart and eventual wife. She was an original member of the creators' Dungeons and Dragons group and played a significant role in their early lives. Her presence unknowingly caused a permanent personal rift between the two business partners before the global contest ever began. She remains an important historical figure to those studying the founders.