Jan Brożek (Ioannes Broscius, Joannes Broscius or Johannes Broscius; 1 November 1585 – 21 November 1652) was a Polish polymath: a mathematician, astronomer, physician, poet, writer, musician and rector of the Kraków Academy.
Brożek was born in Kurzelów, Sandomierz Province, and lived in Kraków, Staszów, and Międzyrzec Podlaski. He studied at the Kraków Academy (now Jagiellonian University) and at the University of Padua. He served as rector of Jagiellonian University.
He was the most prominent Polish mathematician of the 17th century, working on the theory of numbers (particularly perfect numbers) and geometry. He also studied medicine, theology and geodesy. Among the problems he addressed was why bees create hexagonal honeycombs; he demonstrated that this is the most efficient way of using wax and storing honey.
He contributed to a greater knowledge of Nicolaus Copernicus' theories and was his ardent supporter and early prospective biographer. Around 1612 he visited the chapter at Warmia and with the knowledge of Prince-Bishop Simon Rudnicki took from there a number of letters and documents in order to publish them, which he never did. He contributed to a better version of a short biography of Copernicus by Simon Starowolski. "Following his death, his entire collection was lost"; thus "Copernicus' unpublished work probably suffered the greatest damage at the hands of Johannes Broscius."
- "Geodesia distantiarum" (1610);
- "Dissertatio astronomica" (1616);
- "Dissersatio de cometa Astrophili" (1619);
- "Dе dierum inaequalitate" (1619);
- "Arithmetica integrorum" (1620);
- "Apologja pierwsza kalendarza rzymskiego powszechnego" (1641);
- "Apologia pro Aristotele et Euclide" (1652);
- "De numeris perfectis disceptatio" (1637);
- "Epistolae ad naturam ordinariam figurarum plenius intelligendum" (1615);
- "Peripatheticus Cracowiensis";
- "De litterarum in Polonia vet ustate";
- "Sermo in synodo Luceornensi" (1641)
- Discurs Ziemianina z Plebanem (Discourse between the Squire and the Vicar, 1625)
- Gratis, albo Discurs I Ziemianina z Plebanem (Gratis, or Discourse I between the Squire and the Vicar]
- Przywiley, albo Discurs II Ziemianina z Plebanem (Privilege, or Discourse II between the Squire and the Vicar)
- Consens, albo Discurs III Ziemianina z Plebanem (Consensus, or Discourse III between the Squire and the Vicar)
- List of Poles—Astronomy
- List of Poles—Mathematics
- Perfection—Perfect numbers
- Physician writer
- List of Roman Catholic scientist-clerics
- "Ioannes Broscius"
- "Joannes Broscius",
- "Johannes Broscius"
- Nicolaus Copernicus Gesamtausgabe (Nicolaus Copernicus Complete Edition): Die Copernicus-biographien des 16. Bis 18. Jahrhunderts (Copernicus Biographies of the 16th–18th centuries), ISBN 3-05-003848-9
- "Copernicus's unpublished work probably suffered the greatest damage at the hands of Johannes Broscius (1581–1652), professor of mathematics and astronomy at the university of Kraków. Around 1612, Broscius visited Ermland to collect documents for a biography on Copernicus. He took a number of letters and documents with him to Kraków, to utilize them merely for succinct notes and marginalia. Following his death, his entire Copernicus collection was lost." Andreas Kühne, "Copernicanism", Reader's Guide to the History of Science, Taylor & Francis, 2000, ISBN 1-884964-29-X, 9781884964299, p. 152. 
- Jan Chroboczek, Jan Brożek: Mathematician, Astronomer and Biographer of Copernicus (1585–1652), The Polish Review, vol. LV, no. 2, 2010, pp. 169–93.
- Jan Brożek / Joannes Broscius Mathematician, Historian of Science, University Professor and Benefactor
- Galileo Project entry