Rahel is a fraternal twin who shares a profound, almost telepathic connection with her brother, Esthappen. As a seven-year-old in 1969, she is impetuous, flamboyant, and prone to wearing red-tinted plastic sunglasses, resisting the strict conservative rules of her family. As an adult in 1993, she returns home after drifting through architectural school and an indifferent marriage in America, searching for emotional grounding.

Esthappen, known as Estha, is Rahel's fraternal twin brother. In 1969, he is a lively seven-year-old who loves singing Elvis Presley songs and show tunes, sporting a slick pompadour and pointy shoes. As an adult in 1993, he has become a mute, traumatized man who obsessively cleans his room and takes meandering, aimless walks around the town.

Ammu is a passionate, free-spirited woman living in Ayemenem. After leaving her alcoholic, abusive husband in Calcutta to protect herself and her twins, she returns to her conservative parents' home, where she is treated as a disgraced burden. She deeply loves her children but struggles with the stifling expectations of her patriarchal society.

Velutha is a highly skilled carpenter and general maintenance worker at the Paradise Pickles & Preserves factory. Because he is a Paravan, he is classified as an "untouchable" under the region's strict caste system, yet he carries himself with quiet dignity and quiet confidence. He acts as an autodidact, a communist sympathizer, and the caretaker for his disabled older brother.

Baby Kochamma is the great-aunt of Rahel and Esthappen. In her youth, she converted to Catholicism and briefly became a nun to pursue a doomed infatuation with an Irish monk. By her eighties, she is morbidly obese, resentful, and obsessed with American television reruns, using her position in the family to manipulate those around her out of spite and paranoia.

Chacko is Ammu's brother and the manager of the family's Paradise Pickles & Preserves factory. An Oxford-educated Rhodes scholar, he fancies himself a Marxist intellectual and a worldly bon vivant, though he spends much of his time building flimsy balsam model airplanes. He returns to India after his marriage collapses in England.

Margaret is Chacko's British ex-wife and Sophie's mother. She works as a waitress when she first meets Chacko at Oxford, initially drawn to his intellect before growing tired of his slovenliness. Recently widowed after the death of her second husband in a car accident, she accepts Chacko's invitation to bring Sophie to India for Christmas.

Sophie is the eight-year-old British daughter of Chacko and Margaret. With her pale skin, blonde hair, and blue eyes, she is treated as a favored guest by the Indian side of her family. She is confident, occasionally rude, and largely uninterested in building a bond with her biological father.

Baba is Ammu's ex-husband and the father of the twins. He works as an assistant manager on a tea estate in Calcutta until his severe alcoholism threatens his job. He relies on violence and manipulation, ultimately destroying his marriage.

Pillai is the foreman of the Paradise Pickles & Preserves factory and the proud head of the communist underground in Ayemenem. He is a pragmatic political operator who views Chacko's intellectual communism with skepticism and warns him about employing untouchables.

The Orangedrink Lemondrink Man is a vendor with "gummy eyes" who operates the lobby concession stand. He uses his position and free cold drinks to lure young boys behind the counter.

Ammu and Chacko's mother is the nearly blind matriarch of the Ipe family. She endures a miserable marriage to a harsh husband and redirects her bitterness toward her daughter, whom she views as a disgrace, and her former daughter-in-law.

Ammu's father was a frustrated amateur entomologist who spent his life bitter over not receiving credit for discovering a specific species of moth. He ruled his family with a harsh, dour demeanor.

Velutha's father is an older Paravan who adheres strictly to the traditional caste boundaries. Terrified by his son's independence and disregard for social rules, he remains loyal to the upper-caste Ipe family at the expense of his own blood.

Kochu Maria is the dwarf maid employed by the Ipe family. In 1993, she spends most of her time sitting with Baby Kochamma, eating peanuts and watching outdated American talk shows while ignoring the deteriorating state of the house.