Ekaterina Ivanovna Desnitskaya (April 27, 1886, Lutsk, January 3, 1960, Paris) was a Russian noblewoman, a participant in the Russo-Japanese War, and a recipient of the Order of St. George (1904). She was married to the Siamese prince Chakrabon in 1906 and again in 1919. Their love story has been reflected in several literary works.

In 1904, Desnitskaya met Prince Chakrabon, the second son of King Rama V, who was studying military affairs in St. Petersburg and graduated from the Page Corps in 1902. They married in 1906, with the ceremony taking place at the Greek Church of the Holy Trinity in Constantinople. Ekaterina wrote to her brother about how much she loved and respected her husband, despite many seeing their marriage as merely one of wealth and luxury. The Siamese royal family initially reacted coldly to their union, and the prince was excluded from the line of succession.

On March 28, 1908, they had a son, Chula (th:พระเจ้าวรวงศ์เธอ พระองค์เจ้าจุลจักรพงษ์). After his birth, the attitude towards Chakrabon improved. Ekaterina tried to adapt to her new life: she learned the Thai language, respected local customs, and built a relationship with her mother-in-law.

In 1919, their marriage fell apart due to Chakrabon's desire to marry his cousin Chavalit. Ekaterina tried to save the family, pleading with her husband for sympathy and confessing her love, but she did not want to be the third wheel.

In 1919, she moved to Shanghai, where her brother lived and there was a large Russian diaspora. Later, Ekaterina married an American, Harry Clinton Stone. They eventually moved to Paris, where she spent the rest of her life.