Mahmoud Da'as (, also known by his "kunya" Abu Khalid; 1934 – 2009) was a high-ranking commander of the Palestine Liberation Organisation (PLO), serving as long-time member of Fatah's Revolutionary Council and Supreme Military Council. Born in northern Palestine, Da'as grew up in Jordan where he joined the Jordanian Armed Forces (JAF). Educated as military engineer, he was eventually appointed lieutenant colonel and head of the Jordanian Engineering Corps' 2nd Battalion. Da'as joined the PLO in 1967, and defected from the JAF during the Black September of 1970. He consequently rose in the ranks of the PLO, and became an important military commander in the Arab–Israeli conflict, taking part in missions in Lebanon, Yemen, Sudan, and Uganda. Following the Oslo I Accord, Da'as became President Yasser Arafat's personal military advisor and a deputy in the Palestinian Legislative Council.