Mercenaria is a genus of edible saltwater clams, marine bivalve molluscs in the family Veneridae, the Venus clams. The genus Mercenaria includes the quahogs, consisting of Mercenaria mercenaria, the northern quahog or hard clam, and M. campechiensis, the . These two species commonly hybridise where their ranges overlap. Other species within the genus include the venus clam M. stimpsoni found in north Pacific waters. All these species were formerly placed in the related genus Venus.