Megiddo (Hebrew: מגידו‎; Arabic: المجیدو‎, Tell al-Mutesellim) is a tell in modern Israel near Kibbutz Megiddo, known for its historical, geographical, and theological importance, especially under its Greek name Armageddon. In ancient times Megiddo was an important city-state. Excavations have unearthed 26 layers of ruins, indicating a long period of settlement. Megiddo is strategically located at the head of a pass through the Carmel Ridge overlooking the Jezreel Valley from the west.

Megiddo is also known as Greek: Μεγιδδώ/Μαγεδδών, Megiddó/Mageddón in the Septuagint; Latin: Mageddo; Assyrian: Magiddu, Magaddu; Magidda and Makida in the Amarna tablets; Egyptian: Maketi, Makitu, and Makedo. The Book of Revelation mentions apocalyptic military amassment at Armageddon, a name derived from the Hebrew "Har Megiddo" meaning "Mount of Megiddo". The word has become a byword for the end of the age.

Megiddo was a site of great importance in the ancient world. It guarded the western branch of a narrow pass and trade route connecting Egypt and Assyria. Because of its strategic location, Megiddo was the site of several historical battles. The site was inhabited from approximately 7000 BC to 586 BC (the same time as the destruction of the First Israelite Temple in Jerusalem by the Babylonians, and subsequent fall of Israelite rule and exile). Since this time it has remained uninhabited, preserving ruins pre-dating 586 BC without settlements ever disturbing them. Instead, the town of Lajjun (not to be confused with the el-Lajjun archaeological site in Jordan) was built up near to the site, but without inhabiting or disturbing its remains.