Ermengol or Armengol VIII (1158–1208), known as el de Sant Hilari ("the one from Sant Hilari") was the count of Urgell from 1184 until his death.
He was a son of Ermengol VII and Dulce, daughter of Roger III of Foix.
[1] During his reign, the decline of his house was initiated at the hands of the viscounts of Àger.
In 1206, a period of disorder commenced owing to the ambitions of Guerau IV of Cabrera, who disputed the right of Aurembiaix to succeed.
Ermengol extracted a promise from Peter II of Aragon to defend the rights of his widow and daughter.