A new distinct cultivar of Osteospermum plant named `Sunny Marina`, characterized by its single, daisy type composite inflorescenses with elliptic ray florets and tubular disc florets; violet to light purple disc florets and light purple ray florets with gray-orange undersides; dark green to yellow-green, small and narrow leaves; ovate to spatulate leaves with 6-8 small, acute lobes; and short peduncles and compact bushy plant shape.