The weakfish, Cynoscion regalis, is a marine fish of the drum family Sciaenidae.

A medium-large, slender, marine fish, it is found along the east coast of North America. The head and back of this fish are dark brown in color with a greenish tinge. The sides have a faint silvery hue with dusky specks, and the belly is white. The origin of its name is based on the weakness of the mouth muscles, which often cause a hook to tear free, allowing the fish to escape. The weakfish grows to 1 m (3 feet) in length and 9 kg (20 pounds) in weight. It is found along the eastern coast of North America from Nova Scotia, Canada to northern Florida, where it is fished both commercially and recreationally.