Miles of Plancy (died 1174), also known as Milon or Milo, was a noble in the crusader Kingdom of Jerusalem.

He was born in Champagne and came to the east in the 1160s, where he served King Amalric I, to whom he was distantly related. Amalric made him seneschal of Jerusalem, and in 1167 he participated in Amalric's expedition to Egypt. He encouraged Amalric to make a treaty with Egypt rather than capturing it by force and submitting it to plunder; after Amalric returned home, Egypt quickly fell under the control of Nur ad-Din and his commander Shirkuh. This event would eventually lead to the union of Egypt and Syria under Saladin, an inauspicious outcome for the crusader kingdom.

In 1170 a fortress was built at Gaza by the Knights Templar, to defend against attacks from Egypt. Miles would not allow the unarmed inhabitants of the city to take shelter inside and many of them were killed when the city was attacked. In 1173 he married Stephanie of Milly, daughter of Philip of Milly and widow of Humphrey III of Toron . He was given the castle of Montreal, and through his marriage to Stephanie he became Lord of Oultrejordain.

In 1174 Amalric died and Miles acted as an unofficial regent for his son and successor Baldwin IV, who, although stricken with leprosy, was crowned king in his own right. The chronicler William of Tyre did not like him, calling him "a brawler and a slanderer, ever active in stirring up trouble," and Miles insulted the other barons of the kingdom, especially those who were native easterners, by refusing to consult them on any matter. Count Raymond III of Tripoli came to Jerusalem and claimed the regency as Baldwin's nearest male relative. Raymond was supported by the other powerful native barons, including Humphrey IV of Toron (Miles' stepson, the son of Stephanie and Humphrey III), Baldwin of Ibelin and Balian of Ibelin. In the autumn of 1174 Miles was assassinated in Acre, by unknown persons, although there is no direct evidence that Raymond was involved. William of Tyre heard rumours that the assassination occurred because Miles was so fiercely loyal to Baldwin IV, or because he was plotting to take over the kingship with help from his relatives in France.

Within days, the Haute Cour officially designated Raymond regent. Stephanie married another relative newcomer, Raynald of Chatillon, in 1176.