title: Jan I
text: # Jan I
  
  Jan I may refer to:
  
  * Jan I the Scholastic (1308/10 – by 1372)
  * John I, Duke of Opava-Ratibor (c.  1322 – c.  1380 or 1382)
  * Jan I van Brederode (1370/1372 – 1415)
  * Jan I, Duke of Żagań (c. 1385 – 1439)
  * Jan I Olbracht (1459–1501), King of Poland
  