Úrsula Iguarán is the Buendía family matriarch. As a young woman, she marries her cousin, José Arcadio Buendía. Together with other young couples, they found the town of Macondo and begin their family there. Her mother convinces her that the result of any incestuous relationships, such as Úrsula's with her husband, will necessarily be a child born with a pig's tail, so Úrsula retains a lifelong fear of that possibility.

She founds a prosperous business in Macondo selling candy animals and raises the next four generations of Buendías. Her husband, always obsessive, becomes mentally ill, and she visits him every day to assist him with daily life tasks. When her sons and grandsons engage in military activity, with one going so far as to install himself as the leader of Macondo, she ensures they follow her will with violence. She refuses to let anyone else in the family take the gold that a guest left in the Buendía house during the war years, even when the family lives in poverty.

Úrsula is the archetypal matriarch, watching over the Buendía family for many generations. Her long life symbolizes the central role of the mother in Latin American culture. She is not only a maternal figure but also a successful businesswoman and community leader.