Stanislovas Svetkus Rapolionis (Latin: Stanislaus Rapagel(l)anus, Stanislaus Lituanus, Polish: Stanisław Rafajłowicz; c. 1485 or 1500 – May 13, 1545) was a Lutheran activist from the Grand Duchy of Lithuania. With patronage of Albert, Duke of Prussia, he obtained the doctorate of theology from the Protestant University of Wittenberg where he studied under Martin Luther and Philip Melanchthon. After graduation, he became the first professor of theology at the newly established University of Königsberg, also known as Albertina. As professor he began working on several Protestant publications and translations, including a Bible translation into Polish. It is believed that he also started the first first translator of the Bible into Lithuanian. Together with Abraomas Kulvietis, Rapolionis was one of the very first authors to write in the Lithuanian language. While Rapolionis and Kulvietis died early leaving their work unfinished, they laid the foundations for future Lithuanian writers and translators.
Very little is known about Rapolionis' life prior to his studies at the University of Wittenberg in 1542 and most of his early biography is a conjecture. He hailed from a petty Lithuanian noble family from the area of Eišiškės that possibly used the Działosza coat of arms (image similar to Działosza was added next to his name in a registry at the University of Königsberg). His date of birth is unknown. In 1726, Michael Lilienthal wrote that Rapolionis died at age 60 which would put his date of birth around 1485. However, newer publications usually list his date of birth as c. 1500.