The greater horseshoe bat (Rhinolophus ferrumequinum) is an insectivorous bat of the genus Rhinolophus. Its distribution covers Europe, Northern Africa, Central Asia and Eastern Asia. It is the largest of the horseshoe bats in Europe and is thus easily distinguished from other species. The species is sedentary, typically travelling up to 30 kilometres (19 mi) between the winter and summer roosts, with the longest recorded movement being 180 km (110 mi). The frequencies used by this bat species for echolocation lie between 69–83 kHz, have most energy at 81 kHz and have an average duration of 37.4 ms.

The greater horseshoe bat is the largest horseshoe bat in Europe. It has a distinctive noseleaf, which has a pointed upper part and a horseshoe-shaped lower part. Its horseshoe noseleaf helps to focus the ultrasound it uses to 'see'. The greater horseshoe bat also has tooth and bone structures that are distinct from that of other rhinolophids. Its first premolar on the upper jaw protrudes from the row of teeth. For other horseshoe bats, this premolar is very small or non-existent. Also in comparison to its relatives, the greater horseshoe bat has relatively short third and fourth metacarpal bones in its wings. It also lacks a tragus. The greater horseshoe bat is, on average, between 57–71 millimetres (2.2–2.8 in) long, with a 35–43 mm tail (1.4–1.7 in) and a 350–400 mm wingspan (14–16 in); Rhinolophus ferrumequinum also exhibits slight sexual dimorphism, with females being slightly larger than males. The fur of the species is soft and fluffy, with the base of hairs being light grey, the dorsal side hair grey brown and the ventral side grey-white, with juvenile bats having more of an ash-grey tint to their fur. Wing membranes and ears are light grey-brown. The greater horseshoe bat weighs up to 30 grams (1.1 oz) and can live up to 30 years.

The greater horseshoe bat ranges from North Africa and southern Europe through south-west Asia, the Caucasus, Iran, Afghanistan, Pakistan and the Himalayas to south-eastern China, Korea, and Japan. The northernmost occurrence is in Wales. Reaches to the southern parts of the Netherlands, Germany, Poland and Ukraine. Generally the bats live below 800 m asl (above sea level), but it also lives, depending on roost availability and humidity, 3,000 m asl in the Caucasus.

Pastures, deciduous temperate woodland, Mediterranean and sub-mediterranean shrubland and woodlands are common foraging habitats for this species. In northern parts of its range, the horseshoe uses warm underground sites, both natural and artificial, as summer roosts as well as attics. Where the species occupies buildings, proximity to good foraging areas and underground sites for torpor at various times of year and for winter hibernation as well as the building's own features are important.

Horseshoe bats hibernate in cold underground sites during the winter. The bats require a certain temperature and humidity limit, but this can vary with age, sex and condition. Horseshoe bats are active throughout the year in the southern parts of their range. Horseshoe bats commonly travel distances of 20–30 km between winter and summer roosts, with longest distance recorded being 180 km. Horseshoe bats also live in montane forests among the mountains and valleys of the Himalaya in South Asia and roosts in caves, old temples, old and ruined buildings in tight clusters.

The species feeds preferentially on lepidopterans (moths), making up around 41% of the diet - in particular the noctuid species. For example, the species preys on the lesser wax moth by identifying the moth's high frequency mating call. Coleopterans (beetles) constitute around 33% of the diet, of which dung beetles and cockchafers are often taken. Aphodius rufipes is one such dung beetle forming an especially important part of its diet. (Cow pats are part of its life cycle, acting as a food source and habitat for the larvae. Up to 100 larvae can be found in a single cow pat; while the adult beetle is most abundant in August when the young bats begin their first feeding flights.) The remainder of the diet consists of species of Hymenoptera and Diptera, as well as cave spiders.

The feeding area from the maternity roost is typically of radius 4 km, as neither the lactating females or young can travel far. In late August and September the bats feed on cranefly, to fatten up before hibernation. Breeding females depend on beetles from April until June, and moths from June to August.

The greater horseshoe bat leaves its roost at dusk. Its flying is made up of slow, fluttering travel with short glides, normally between 0.3 and 6 metres above the ground. Little hunting is done during wet and windy weather. It hunts in terrain with poor tree cover such as hillsides and cliff faces, and in gardens where it locates insects from a resting place and then intercepts them. The species has the ability to pick food up off the ground while still in flight, and indeed drinks during low-level flight or while hovering. The feeding range of colonies in England is between 8 and 16 kilometres.