Heberto Sein (1898–1977) was a Mexican Quaker leader, peace activist, language interpreter and diplomat.[1]
Born in Matehuala, San Luis Potosí, Mexico, Sein was a founder of the Mexico City Friends Meeting and Friends House. He was married to a Swiss-born Quaker, Suzanne Sein.[1] He was an interpreter at the founding of the League of Nations and later with the International Labor Organization.[1] He also promoted the workcamps of the American Friends Service Committee in Mexico.[1] He was part of the larger struggle in Latin America for non-violent social change.[2] He was often invited to speak on peace in the United States, and was a strong yet tactful voice at international peace conferences throughout the world.[3] The Casa Heberto Sein, a Quaker Center in Hermosillo, Sonora, Mexico is named for him.