Ballyfermot (Irish: Baile Formaid) is a suburb in the city of Dublin, Ireland. Located seven kilometres west of the city centre, south of the Phoenix Park, it is bordered on the north by Chapelizod, on the south by Walkinstown, on the east by Inchicore, on the north-west by Palmerstown and the south-west by Clondalkin. The River Liffey lies to the north, and the Grand Canal, now a recreational waterway, lies to the south. Ballyfermot is designated as postal district Dublin 10. Cherry Orchard is also a suburb within Ballyfermot. Ballyfermot is also a civil parish in the barony of Uppercross.

The place name Ballyfermot—rendered in Irish Baile Formaid[1] and sometimes Baile Thormaid[2]—is derived from the Middle Irish baile (“farmstead”),[3] and the Old Norse personal name Þormundr.[4]