ENThe aim of the article is to present three important stages of the life and work of Bishop Justinas Staugaitis: 1) education, 2) pastoral, social, cultural and political activity, 3) holding the office of bishop of the Telšiai diocese. Bishop Staugaitis was a student of the Junior High School in Marijampolė and the Theological Seminary in Sejny, where he took part in the secret activities of Lithuanian seminarians and developed strong national attitudes. The most important contribution he made to Lithuanian culture and education was the founding of the “Žiburys” Benevolent and Educational Society, which operated in the then Suwałki Voivodeship and contributed to raising the level of culture in society. He also edited the magazine “Vadovas” addressed to priests. During World War I, Bishop Staugaitis became involved in the political life of Lithuania and was elected a member of the Lithuanian Council. It was then that he signed the Act of Independence of Lithuania. He was elected to the Lithuanian Constituent Assembly of the first and second terms, in which he served as chairman. After the establishment of the Ecclesiastical Province of Lithuania, J. Staugaitis was appointed ordinary bishop of the Telšiai diocese. Keywords: Bishop Justinas Staugaitis, Seinai Theological Seminary, society “Žiburys”, chair of the Seimas, bishop of Telšiai.