Jan Zamoyski, Polish nobleman (d. 1605)
Jan Sariusz Zamoyski (Latin: Ioannes Zamoyski de Zamoscie; 19 March 1542 – 3 June 1605) was a Polish nobleman, magnate, and the 1st ordynat of Zamość. He served as the Royal Secretary from 1565, Deputy Chancellor from 1576, Grand Chancellor of the Crown from 1578, and Great Hetman of the Crown from 1581.

Zamoyski was the General Starost of the city of Kraków from 1580 to 1585, Starost of Bełz, Międzyrzecz, Krzeszów, Knyszyn and Tartu. An important advisor to Kings Sigismund II Augustus and Stephen Báthory, he was one of the major opponents of Bathory's successor, Sigismund III Vasa, and one of the most skilled diplomats, politicians and statesmen of his time, standing as a major figure in the politics of the Polish–Lithuanian Commonwealth throughout his life.