Franciscanas are found only in eastern South America, in the Atlantic Ocean. They are distributed in coastal and shallow waters between Espírito Santo, in Brazil, and Golfo San Matias, in Argentina, reaching depths of up to 50 meters.

Throughout its distribution, there are different franciscana population stocks, defined as Franciscana Management Areas (FMAs),based mainly on genetic analyses. The franciscana population living in Babitonga Bay was recently recognized as a distinct population.