It inhabits open deciduous woodland, upland moors and open mountainous areas (sometimes above the treeline), natural grasslands, pastures and meadows (Koubek and Zima 1999). In woodland, its diet consists mainly of shrubs and tree shoots, but in other habitats, it also consumes grasses, sedges and shrubs.

Between the 16th and the early 20th century, Red Deer experienced a dramatic decline across most of its European range due to overhunting, deforestation and competition with domestic livestock (Ledger et al. 2022). A general recovery mostly began in the 1950s, thanks to law enforcement and reintroduction programs.

The Red Deer is now widely but somewhat patchily distributed throughout most of continental Europe, although it is absent from northern Fennoscandia and vast areas of European Russia. It is present on a number of islands, including the British Isles, Corsica and Sardinia. In Ireland, Red Deer became locally extinct at the end of the Pleistocene but were reintroduced by humans from Scotland during the Neolithic period. The only population descended from this early introduction is within Killarney, County Kerry. All other populations were introduced during the 19th century from outside of Ireland (Carden et al. 2012). British Red Deer populations are often at various levels admixed with non-indigenous animals and in several areas hybridization with sika deer (Cervus nippon) is not rare (Pérez-Espona et al. 2013, Smith et al. 2018). The import of animals from central and eastern Europe was particularly frequent in English parks. Red Deer is extinct in Albania. In North Macedonia, it went extinct at the beginning of the 20th century but was reintroduced later with animals from Slovenia, Croatia and Serbia (Apollonio et al. 2010). In Belarus, Red Deer was almost completely exterminated by the 18th century and most of the present populations originate from massive reintroductions, 2,400 animals in 1955-1989 and 3,200 animals in 2006-2020, using mainly individuals from Beloveska Forest, but also from the Voronezh Preserve (western Russia), Caucasus, Austria, Hungary and Siberian Wapiti Cervus canadensis (Valnisty et al. 2022). Actually, the native Red Deer of the Białowieża-Beloveska Forest between Poland and Belarus were extirpated at the end of the 18th century and the current population derives from releases of animals of different origin from the end of the 19th century (Jędrzejewska et al. 1997, Niedziałkowska et al. 2012). In Ukraine, the native populations were restricted to the Carpathians, Polesia and Crimea. Unfortunately part of the reintroduction and restocking interventions may have also involved animals from Askania-Nova (southern Ukraine), where during Soviet times researchers experimented with hybridisations with Red Deer from Central Europe and the Caucasus, Sika Deer and Asian Wapiti (Zagorodniuk 2022).

In European Russia, Red Deer were exterminated by 1750, then reintroduced mainly in the 20th century using stocks from Central Europe and the Caucasus, but also from Asian Wapiti (Baskin and Danell 2003); The Mammals of Russia portal (Млекопитающие России 2023) shows presence in In Greece, the last native and pure population is supposed to have survived in the Sithonia Peninsula (Chalkidiki, north-eastern Greece) where it became extinct in the 1980s (Masseti 2012). Another population, on Parnitha Mountain, central Greece, was restocked (Karaiskou et al. 2014). In Bulgaria, native Red Deer live still in the central Balkan Mountains, whereas in other areas mixed populations prevail (Chassovnikarova et al. 2003). In Portugal, most populations result from reintroduction or natural expansion from transborder Spanish populations (Apollonio et al. 2010). In Italy, most of the extant populations originated from recolonisation from neighbouring countries (central and eastern Alps) or from reintroductions (western Alps and Apennine) (Mattioli et al. 2001).

It occurs from sea level to above the tree line (c. 3,000 m) in the Alps. The distribution is much more patchy and fragmented than the apparent continuity suggested by the distribution map.

The global range extends out of the European region to North Africa, the Caucuses, and the Near and Middle East in Anatolia (Türkiye), northern Iran, and Iraq, but it is extinct in Israel, Jordan, Lebanon, and Syria.

It is protected under Appendix III of the Bern Convention. Subspecies C. e. corsicanus is strictly protected under Appendix II of the Bern Convention and Annexes II* and IV of the EU Habitats and Species Directive. The species protected through the Convention on the Conservation of Migratory Species of Wild Animals (Bonn Convention; Annex I: migratory species which are endangered and must be protected by Parties), and trade is controlled through Annex II of CITES (Convention on International Trade in Endangered Species of Wild Fauna and Flora).

It occurs in numerous protected areas across its range and also in protected areas outside its range where it has been introduced. To preserve the genetic integrity of local populations, it is important that the introduction of Red Deer from other areas is stopped, unless there is evidence that they belong to the same taxon (subspecies).

Red Deer in Europe have been affected to a large extent by translocations not only between far distant populations and different subspecies within the continent, but also by imported Wapiti and introduced Sika Deer. As a result, most of the present deer populations of Europe are either known hybrids on a subspecific or even specific level or their breeding background is insufficiently known to exclude such a possibility. Systematic investigation into the history and the genetics of all European Red Deer populations is therefore needed as a base for establishing a European Red Deer Management Plan. Part of this plan should be the identification of unpolluted autochthonous populations of this species and the protection of their genetic integrity, thus preserving as much as possible of what is left of its natural variation. In this respect the following populations are important and should be given a high priority for conservation and research:

Swedish Red Deer (C. e. elaphus)
This subspecies, with original distribution in southern Sweden, has its only remaining population free from admixture in Skåne (Ahlén 1965, Höglund et al. 2013). In the official Swedish Red List produced in 2005, this subspecies was classified as VU (D1) (Gärdenfors 2005).

Norwegian Red Deer (C. e. atlanticus)
All Red Deer occurring in Norway still represent pure C.e. atlanticus, with the only exception of the isolated population on the Island of Otteroy, which has experienced an inflow of genes from introduced Red Deer from Germany and Hungary (Ahlén 1965, Haanes et al. 2010).

Mesola Red Deer (Cervus elaphus italicus)
The Gran Bosco della Mesola Natural Reserve harbours the only autochthonous unmixed population of Red Deer in the Italian peninsula. This indigenous Red Deer represents a separate subspecies recently described (Zachos et al. 2014).The population size dropped to the historically lowest level of 10 animals in 1945-1947. In spring 1998 there were 59 individuals, increased to 150 in 2010 (Ferretti and Mattioli 2012) and 250 in 2022 (Mattioli, unpublished). The Mesola Red Deer C. e. italicus is highly threatened and prone to inbreeding depression. Habitat improvement and reduction of competition with Fallow Deer has helped this subspecies to recover. The establishment of additional populations is recommended with exchanges of animals between them to maintain genetic diversity and minimise the effects of inbreeding (Zachos et al. 2014). A National Conservation Plan for the conservation of Mesola Red Deer has been developed (Lovari and Nobili 2010), and a translocation of some dozens of animals to a protected area in southern Italy is planned for 2023-25.

Tyrrhenian or Sardinian-Corsican Red Deer (Cervus elaphus corsicanus)
The Red Deer of Sardinia is descended from animals introduced by man during Neolithic times (at least 5000, possibly 8,000 years ago; cf. Vigne 1992, Carenti et al. 2014), presumably imported from mainland Italy (Hmwe et al. 2006, Doan et al. 2017). The occurrence of Red Deer in Corsica is documented only from late Classic times, about 1500 years ago (Vigne 1992). Listed as Endangered also in the recent past, now is downlisted to Least Concern, due to the successful reintroductions and the overall numbers.

Iberian Red Deer (Cervus elaphus hispanicus)
Iberian peninsula was an important refugium during the Last Glacial Maximum around 18,000-25,000 years ago. The Iberian subspecies C.e. hispanicusis a relict of the Red Deer populations surviving that rigid period. One of the two sub-lineages was the main source for the post-glacial recolonization of north-western and central Europe (Carranza et al. 2016). The subspecies is considered to be threatened by genetic introgression from introduced animals from other parts of Europe. There have been many introductions of allochthonous Red Deer by private landowners seeking to "improve" the antlers for hunting, only some of which have been documented. (Carranza et al. 2003, Queirós et al. 2020). Also, farm rearing and release after artificial selection is increasing.