Teillier was born in Santa Bárbara, Biobío Region, on October 29, 1943.
He joined the Communist Youth in 1958, serving as regional secretary in the cities of Temuco and Valdivia. He then became regional secretary in Valdivia, where he was caught in the 1973 Chilean coup d'état. In 1974, he held the same post in Concepción and Lota.
In the middle of that year, while participating in a political meeting in Santiago, he was arrested by agents of the Air Force Intelligence Service (Sifa). He was imprisoned for two years in the basements of the Aviation War Academy, where he was tortured.
In 2005, after the death of the leader Gladys Marin, the 9th Plenary Session of the Central Committee elected him interim president of the Party and in November 2006, the 23rd National Congress of the party ratified him in the position, in which he remained until his last moment.
During 2009, he was elected for the first time as deputy of the Republic representing the Party for District Nº 28 (Lo Espejo, Pedro Aguirre Cerda and San Miguel) in the legislative period 2010 to 2014, then he was reelected for the periods 2014-2018, for the same district, and in 2018-2022, for the new 13th District of the Metropolitan Region.
