Mullantiboyle is a townland located in the Barony of Boylagh, within the Civil Parish of Killybegs Lower and the Electoral Division of Glenties, County Donegal.

It spans an area of 391,965 square metres, which equates to approximately 0.15 square miles or 96 acres.

Mullantiboyle shares its borders with Gortnamucklagh to the north, Meenachallow to the east, Derries to the south, and Tullyard to the west.