Count Marcin Kazimierz Kątski of Brochwicz (1636 – 1710) was a Polish nobleman, politician, diplomat, scholar, military commander, General of Artillery of the Crown (1667–1710), the Voivode of Kiev (1684–1702) and Castellan of Kraków (1706–1710).

King John II Casimir funded a scholarship for young Kątski, so that in the years 1653–1657 he would become familiar with the latest trends in the art of war by serving in the French army and commanding together with Marshal Prince Louis de Bourbon in the Netherlands.

In the years 1663 to 1664 as a lieutenant colonel of infantry, he took part in a military expedition of John II Casimir to the Dnieper river in Ruthenia.

He Participated in all of the campaigns of chief captain, Hetman, and later King John Sobieski, including the siege of Vienna in 1683, when Kątski was only an artillery commander.

His effort was visible at the confluence of the Dniester and Zbrucz rivers where a neglected defensive castle developed into the famous fortress and stronghold called Okopy Św.