Elisa Loncón was born in Lefweluan, a Mapuche community near Traiguén, Araucanía Region. One of Loncón's great-grandfathers fought the Chilean government during the invasion of Araucanía (1861–1883) and was a close ally of chief José Santos Quilapán. Loncón's family was involved in the recovery of land ownership before and during the Chilean land reform (1962–1973). As a consequence land recovery activism, Loncón's maternal grandfather, Ricardo Antileo, was jailed during the Pinochet-era military dictatorship. The father of Elisa was a bullock-driver who learned to read by his own means at 17 years old. He later learned furniture carpentry and made this his occupation. Her father's interest in reading and writing led him to buy himself a typewriter. Her mother was a self-employed horticulturist, who provided her family with food and sold vegetables in the local markets. Loncón's mother who was fond of poetry taught her to read.