Countess Clotilde "Klotild" Apponyi de Nagy-Aponyi (née Klothilde Wilhelmine Josepha Gabriele Maria Innocenta von Mensdorff-Pouilly-Dietrichstein; 23 December 1867 – 1 September 1942) was an Austro-Hungarian noblewoman, women's rights activist, politician and a diplomat.

Countess Klothilde Wilhelmine Josepha Gabriele Maria Innocenta was born as a third daughter and youngest child of the Austrian politician Prince Alexander von Dietrichstein-Nikolsburg and his wife, Countess Alexandrine Aline von Dietrichstein-Proskau-Leslie (1824-1906), second daughter and one of the heiresses of Joseph Franz, Prince of Dietrichstein.

As president of the MNSz, she addressed the Hungarian parliament in favor of women's suffrage in 1912, and supported this reform in public in 1918.

After World War I, she, as president of the MNSz, became the spokesperson of the non-socialist women's associations of Hungary in oppose to the leftist MANSz under Cécile Tormay.

Together, they were the parents of three children, one son and two daughters:[4] Countess Clotilde Apponyi died on 1 September 1942, at the age of 74 in Budapest, Hungary.