Jan Magnus Tęczyński (16/17 September 1579 – 17 July 1637), of the Topór coat-of-arms, was a Polish nobleman, later voivode of Kraków, and a major landowner associated with Tenczyn and Rytwiany.
He was the son of Andrzej Tęczyński. He acquired the starostwo of Płock from Stanisław Miński in 1606. He subsequently served as the voivode of Kraków from 1620 until his death. He was the last senator of the Tęczyński family line.
In his youth, Tęczyński traveled in Western Europe and studied in Italy; a book was dedicated to him and his brothers while they were in Padua in 1591. In 1601, the Latin-Polish poet and tutor Andrzej Schoenus dedicated a work to him. He also acted as a patron for the Kraków Academy professor Jan Brożek.
Following his death, his daughter Izabela (died 1667) inherited his estates. She married Łukasz Opaliński on 28 November 1639 at Rytwiany.