McTeague is a large, physically powerful man who works as an unlicensed dentist in San Francisco. Originally from a mining town in Placer County, he is slow-moving and a creature of habit. He prefers a quiet life of routine and possesses little formal education, having learned his trade from a traveling charlatan. His primary ambition is to acquire a large gilded tooth to display outside his window as a business sign.

Trina is a delicate young woman of Swiss-German descent who lives with her parents and younger brother. Recognizable by her heavy crown of blue-black braids, she is initially timid around McTeague but finds herself drawn to his sheer physical size. She demonstrates a deeply ingrained frugality and an overwhelming desire to hoard money, a trait triggered by an unexpected financial windfall.

Marcus is an excitable veterinary assistant who lives in the apartment above McTeague. He covers his insecurities and lack of formal education by delivering passionate, half-understood political rants. Initially generous in stepping aside so his friend can court Trina, his fiery disposition sours when she wins a substantial lottery prize.

Old Grannis is an elderly English bachelor who lives down the hall from McTeague. In addition to running a veterinary hospital, his solitary hobby is binding old pamphlets into books. He is characterized by a childlike innocence and an intense, unspoken romantic longing for his neighbor.

Miss Baker is a retired dressmaker who lives in the room adjacent to Old Grannis. Sporting false curls and withered cheeks, she is deeply concerned with ladylike propriety. She shares a mutual, silent infatuation with Old Grannis, preferring to sit close to their shared wall rather than risk conversation.

Maria is a Mexican woman who works as a cleaner in McTeague's apartment building. She frequently scavenges junk and steals small items from the lodgers to sell to a local junk dealer. She is prone to mental lapses and obsessively recounts an unlikely tale about her family's lost solid gold dining service.

Zerkow is a Polish junk dealer who lives and works in a squalid alleyway hovel. He is consumed by an insatiable greed for gold and material wealth. This obsession makes him the perfect, captivated audience for Maria's recurring story about a massive gold service.

Mr. Sieppe is Trina's father, a small man of military bearing who takes himself and his daily affairs very seriously. He treats trivial family outings like rigorous military exploits, barking orders at his children.

Mrs. Sieppe is Trina's practical mother, who frequently worries over her family's social standing and financial stability. She provides a maternal, guiding presence for Trina during her early courtship with McTeague.

August, often referred to by his family as "Owgooste," is Trina's younger brother. A young boy who often serves to underline the awkwardness and lack of sophistication of his family's social outings.

Uncle Oelbermann is Trina's uncle and a prosperous toy store owner. He provides Trina with an investment opportunity for her lottery winnings, paying her monthly interest and offering her piecework whittling wooden toy animals.

The Other Dentist is McTeague's local rival, a flashy professional who wears stylish clothes and behaves like a man about town. He represents the legitimate, sophisticated dental establishment that McTeague lacks the credentials to join.

Heise is a local harness-maker who frequents Frenna's saloon. He serves as a willing ear for Marcus's grievances and occasionally socializes with the main cast of characters over whiskey.

Alexander is Marcus's Irish setter. He maintains an intense, ongoing rivalry with a neighbor's dog, though their interactions often amount to loud growling rather than actual physical conflict.

Selina is Trina's cousin who occasionally joins the family for social outings. She provides musical entertainment during family celebrations.

Cribbens is a prospector operating out of the desert town of Keeler, California. He invites new arrivals to partner with him in searching for gold across the harsh desert terrain.