The Mamre Oak, also known as Abraham's Oak, is a tree under which, according to the Bible, Abraham met God. The Bible states that the Lord appeared to Abraham at the oak grove of Mamre while he was sitting at the entrance of his tent in the heat of the day (Genesis 18:1). Abraham offered three angels, who came to him in the guise of travelers, to rest under this tree (Genesis 18:4). According to tradition, the tree has survived to this day and is an evergreen Palestinian oak (lat. Quercus calliprinos), which is believed to be around 5000 years old.

The oak is located on the grounds of the Russian Monastery of the Holy Trinity in Hebron, approximately 3 km northwest of the Cave of Machpelah, on the West Bank of the Jordan River, in the Palestinian Authority.

This tree is known in the traditions of Christians, Jews, and Muslims, who associate it with the biblical grove of Mamre, considering it a remnant of that grove.

The tree was discovered by the head of the Russian Spiritual Mission in Jerusalem, Archimandrite Antonin (Kapustin). He explored the surroundings of Hebron and compared his observations with biblical texts and local stories. In 1868, he purchased the land where the oak grew. This site became popular among Russian pilgrims, and over time, the holdings of the Russian Church expanded. In the 20th century, the Holy Trinity Monastery was built nearby. After the 1917 revolution, the land came under the jurisdiction of the Russian Orthodox Church Outside Russia.