Mullaghmast (Irish: Mullach Maistín; modern English spelling: Mullamast[1]) is a hill in the south of County Kildare, Ireland, near the village of Ballitore and near the borders with counties Wicklow, Laois and Carlow.

It is classed as a National Monument by the Department of the Environment, Community and Local Government.

The Metrical Dindshenchas, or Lore of Places, a Middle Irish collection of poetry purporting to explain the origins of Irish place names, claims that Mullaghmast is named for Maistiu, wife of Dáire Derg, who was killed by the sorcery of the malicious faery Gris, who was in turned killed by Dáire Derg.

[citation needed] A rebellion had been launched by Rory O'More whose forces burnt Naas in 1577.

The 40 lords of Laois and Offaly and their families were invited to a peace conference by Sir Henry Sidney on or around New Year's Day 1578; Sidney rose and left the unarmed lords and their wives, children and followers, and all except one were killed by Sidney's men, leaving the castle strewn with body parts and drenched in blood.