Mitsuko Thekla Maria, Countess of Coudenhove-Kalergi (German: Mitsuko Thekla Maria Gräfin von Coudenhove-Kalergi; 7 July 1874 – 27 August 1941), formerly known as Mitsu Aoyama (????), was one of the first Japanese people to immigrate to Europe, after becoming the wife of an Austro-Hungarian diplomat, Heinrich von Coudenhove-Kalergi, in Tokyo.
She was the mother of Richard von Coudenhove-Kalergi.