Ermengol (or Ermengaud) (870-937) was a son of Odo of Toulouse and Garsindis. His father gave him the County of Rouergue and Quercy in 906 and he governed it to his death. His brother was Raymond II of Toulouse and together they governed the vast patrimony of their house in the first half of the tenth century.

In 930, he donated property to the abbey of Vabres