Archduke Karl Ferdinand of Austria (Vienna, 29 July 1818 – Gross Seelowitz (Židlochovice Castle), 20 November 1874) was the second son of Archduke Charles, Duke of Teschen (1771–1847) and Princess Henrietta of Nassau-Weilburg, and the maternal grandfather of King Alfonso XIII of Spain.

A son of the "hero of Aspern", he started his military career in Infantry Regiment 57 in Brno.

Later, he received command of a brigade in Italy and fought against the insurgents in Prague in 1848.

He became a lieutenant field marshal of the Austrian Army.

[2] In Vienna, on 18 April 1854, Karl Ferdinand married his first cousin, Archduchess Elisabeth of Austria (1831–1903), the widow of Archduke Ferdinand of Austria-Este, the daughter of Archduke Joseph of Austria, Palatine of Hungary and the mother of Queen Maria Theresia of Bavaria.