Blackfin are found in the tropical and warm temperate waters of the western Atlantic. The range of this species extends from Brazil to Cape Cod, including the Caribbean and the Gulf of Mexico. Blackfin often feed near thesurface, and they frequently form large mixed schools with skipjack.

The blackfin's spawning grounds are believed to be well offshore. Off Florida the spawning season extends from April to November with a peak in May, while in the Gulf of Mexico it lasts from June to September.