Piotr Kmita Sobieński, Piotr Kmita Sobiński of the Kmita (Kmitowie) noble family, Count of Wiśnicz, Szreniawa, (Latin: Petrus Kmita de Wisnicze, Petrus Cmitha in Wissnicze, also Kmitha, Ukrainian: Петро, Кміта, Slovak:, Hungarian: Peter Kmita of Sobnia, b. in 1477, d. 31 October 1553) was Grand Marshal of the Crown from 1529 onwards, voivode and starosta of Kraków, starosta of Spiš (1522 – 1553), starosta of Przemyśl, starosta of Koleński, Castellan of Sandomierz, one of the richest and most influential persons in contemporary Poland. He was the heir of 28 villages, including Wiśnicz, Sobienia and many royal estates, among others, Lipnica Murowana.
He was the younger son of Stanisław Kmita and Katarzyna of Tarnowski, husband of childless Barbara Kmita of Herburtów, who inherited from him, among other things, Lesko and Zagórz). Grandson of Jan Kmita and brother in law to Jan Herburt. An educated person who was a lover of books. He gathered a considerable amount of books in the castle Wiśnicz. He was also an ardent supporter of Erasmus of Rotterdam.
He spent his youth at the court of Emperor Maximilian I, where he distinguished himself for his military valor and humanistic refinement. He fought the Tatars in the Battle of Wisniowiec and the Russians in the Battle of Orsha, and in 1520 he took part in the war against the Teutonic Knights. In 1518, he became Marshal of the Crown Court and in 1522 member of the Polish parliament on the Reich of Nuremberg. In 1524 he defeated the Turkish army in Terebovl. In 1520 he received from Sigismund I the Old the right to collect tributes on the roads to Ustjanowa Dolna.