Jack mackerels or saurels are marine fish in the genus Trachurus of the family Carangidae. The name of the genus derives from the Greek words trachys ("rough") and oura ("tail"). Some species, such as T. murphyi, are harvested in purse seine nets, and overfishing has sometimes occurred.

The Carangidae are a family of ray-finned fish that includes the jacks, pompanos, jack mackerels, runners, trevallies, and scads. It is the largest of the six families included within the order Carangiformes. Some authorities classify it as the only family within that order but molecular and anatomical studies indicate that there is a close relationship between this family and the five former Perciform families which make up the Carangiformes.