Fissurella radiosa is a species of sea snail, a marine gastropod mollusk in the family Fissurellidae, the keyhole limpets.

Two subspecies :

• Fissurella radiosa radiosa Lesson, 1831 (represented as Fissurella radiosa Lesson, 1831)
• Fissurella radiosa tixierae Métivier, 1969

 The size of an adult shell varies between 18 mm and 55 mm.

Distribution: This species occurs in the Atlantic Ocean off the Falkland Islands and the Straits of Magellan of Argentina and Tierra del Fuego.