The son of José Arcadio (II) and Pilar Ternera, Arcadio is roughly the same age as his aunt Amaranta. A seemingly a gentle boy, he becomes schoolmaster of the town. When his uncle Colonel Aureliano Buendía places him in charge of Macondo during the uprising, Arcadio becomes a ridiculous dictator obsessed with order that only his grandmother Úrsula can stop. Arcadio tries unsuccessfully to force Pilar Ternera (his mother) to sleep with him and instead marries Santa Sofía de la Piedad. He is the father of Remedios the Beauty, and the twins Aureliano Segundo and José Arcadio Segundo. He is executed when the Conservatives retake the village.
When Arcadio (José Arcadio III) tries to sleep with Pilar Ternera (the mother he never knew), Pilar pays Santa Sofía de la Piedad to sleep with him instead. She marries Arcadio and bears him three children: Remedios the Beauty, and twin boys Aureliano Segundo and José Arcadio Segundo. After her husband's death, she quietly joins Úrsula in seeing to the needs of the family. Colonel Aureliano asks her to destroy all his love poems; José Arcadio Segundo makes her promise to slit his throat when he dies to ensure he's not buried alive. When she grows old and tired, she simply walks out of the house, never to be heard from again.