A crane fly is an insect in the family Tipulidae. Adults are very slender, long-legged flies that may vary in length from 2–60 millimetres (0.079–2.4 in) (tropical species may exceed 100 millimetres or 3.9 inches).
In the United Kingdom, Ireland and Newfoundland they are commonly referred to as daddy long-legs, but this name can also refer to two unrelated arthropods: members of the arachnid order Opiliones (especially in the United States and Canada) and the cellar spider Pholcidae (especially in Australia). The larvae of the European Crane Fly are commonly known as Leatherjackets. These larvae can cause damage to lawns by feeding on the roots of grass plants.