Ermengarde (Occitan: Ermengarda, Ainermada, or Ainemarda) (b. 1127 or 1129 – d. Perpignan, 14 October 1197), was a viscountess of Narbonne from 1134 to 1192. She was the daughter of Aimery II of Narbonne and his first wife, also named Ermengarde.
Aimery II was killed at the Battle of Fraga on July 17, 1134, fighting against the Almoravids along with Alfonso I of Aragon. Aimery left only two underaged daughters as his heirs, Ermengarde and her half-sister Ermessinde (daughter of Aimery's second wife, also named Ermessinde). Aimery had at least one son, also called Aimery, attested in numerous charters, but he predeceased him (ca. 1130). Thus, the approximately five-year-old Ermengarde inherited the viscounty of Narbonne, which occupied a strategic place in the politics of Languedoc: it was desired by the Counts of Toulouse, the Counts of Barcelona, the Trencavel viscounts of Carcassonne, and the Lords of Montpellier.
In 1142, Alphonse, whose wife Faydid of Uzes had either recently died or been repudiated, married the now-adolescent Ermengarde. In reaction to this prospect, which overturned the balance of power in the region by adding Narbonne to the direct control of Toulouse, a coalition of Occitan lords led by Roger II of Béziers, viscount of Carcassonne, Béziers, Albi and Razès formed an alliance against Toulouse. Alphonse was defeated by the coalition and taken prisoner, and was forced to make peace with Narbonne and restore Ermengarde and her new husband to the viscounty before being released. Following the dissolution of her marriage to Alphonse, Ermengarde was married to a vassal of Roger II, Bernard of Anduze.