Mullion Island is an uninhabited island on the eastern side of Mount's Bay, Cornwall, in the United Kingdom. It is approximately half a mile offshore from Mullion Cove, 1 mile (1.6 km) in circumference and the highest point is 118 feet (36 m) above sea level. It forms part of the Lizard Peninsula Area of Outstanding Natural Beauty and is within the Mullion Cliff to Predannack Cliff Site of Special Scientific Interest.

The Lizard is a peninsula in southern Cornwall, England, United Kingdom. The most southerly point of the British mainland is near Lizard Point at SW 701115; Lizard village, also known as The Lizard, is the most southerly on the British mainland, and is in the civil parish of Landewednack, the most southerly parish. The valleys of the River Helford and Loe Pool form the northern boundary, with the rest of the peninsula surrounded by sea. The area measures about 14 by 14 miles. The Lizard is one of England's natural regions and has been designated as a National Character Area 157 by Natural England. The peninsula is known for its geology and for its rare plants and lies within the Cornwall Area of Outstanding Natural Beauty (AONB).