Bayt Mahsir was a Palestinian Arab village in the Jerusalem Subdistrict. It was depopulated during the 1947–48 Civil War in Mandatory Palestine on May 10, 1948, by the Harel Brigade of Operation Makkabi. It was located 9 km west of Jerusalem.

The Jerusalem Subdistrict was one of the subdistricts of Mandatory Palestine. It was located in and around the city of Jerusalem. After the 1948 Arab–Israeli War, on the Israeli side of the Green Line, the district was integrated into the Jerusalem District. On the other side, the West Bank was annexed into Jordan, the subdistrict was merged with Ramallah Subdistrict to form Jerusalem Governorate, one of three Jordanian governorates in the West Bank.