Cornac () is a commune in the Lot department in south-western France.
The toponym Cornac describes the domain of the Gallic Cornos. This names origin could be based on the Indo-European word Cor meaning escarpment and neh Gaulish for height. The ending -ac comes from the Gallic suffix -acon (itself from the common Celtic *-ÃÂko-), often Latinized as -acum in texts.
The town was part of the lands owned by the barons of Castlenau-Bretenoux. The town originally had a wall and two gates, but these were dismantled in 19th century. The chateau was rebuilt in the 18th century.