Ermengol or Armengol V (1078–1102), called El de Mollerussa ("He of Mollerussa"), was the count of Urgell from 1092 to his death. He was the son of Ermengol IV and his first wife, Lucy (Lucía) of Pallars.
Ermengol was a minor of thirteen when he succeeded his father. A single coin find suggests that he was under the regency of Count Roger II of Foix until he came of age in 1094 or 1095. He spent most of his life in Castile, where he met and married María Pérez, daughter of Pedro Ansúrez, lord of Valladolid, in 1095. During his long absences in Castile, he left the government of Urgell to Guerau II of Cabrera. He died in 1102 at the Battle of Mollerussa.
His children were: