The following is an overview of the fictional peoples and races that appear in J. R. R. Tolkien's fantasy world of Middle-earth. Seven peoples or races are listed in Appendix F of The Lord of the Rings as inhabiting Middle-earth: Elves, Men, Dwarves, Hobbits, Ents, Orcs and Trolls. In addition, Middle-earth is overseen or inhabited by various spirits, known as Valar and Maiar. Other beings inhabit Middle-earth whose nature is unclear, such as Tom Bombadil and his wife Goldberry.
The Ainur were angelic spirits created by Eru Ilúvatar at the Beginning. The Ainur who subsequently entered the physical world of Middle-earth were the Valar ("powers"), though that term came to refer primarily to the mightiest among them. Lesser spirits were called the Maiar. Most of the Valar and Maiar withdrew from Middle-earth to the Undying Lands of Valinor, though some of the Maiar, such as the Wizards or Istari, Melian, and the Dark Lord Sauron, assumed mortal forms to help or hinder the peoples of Middle-earth.
The wizards of Middle-earth are Maiar: spirits of the same order as the Valar, but lesser in power. Outwardly resembling Men but possessing much greater physical and mental power, they are also called the Istari (Quenya for "Wise Ones") by the Elves. They were sent by the Valar to assist the people of Middle-earth to contest Sauron. The first three of these five wizards were known in the Mannish tongues of the Lord of the Rings series as Saruman "man of skill" (Rohirric), Gandalf "elf of the staff" (northern Men), and Radagast "tender of beasts" (possibly Westron). Tolkien never provided non-Elvish names for the other two; one tradition gives their names in Valinor as Alatar and Pallando, and another as Morinehtar and Rómestámo in Middle-earth. Each wizard in the series had robes of a characteristic colour: white for Saruman (the chief and the most powerful of the five), grey for Gandalf, brown for Radagast, and sea-blue for Alatar and Pallando (known consequently as the Blue Wizards or "Ithryn Luin"). Gandalf and Saruman both play important roles in The Lord of the Rings, while Radagast appears only briefly. Alatar and Pallando do not feature in the story, as they are said to have journeyed far into the east after their arrival in Middle-earth.
As the Istari were Maiar, each one served a Vala in some way. Saruman was the servant and helper of Aulë, and so learned much in the art of craftsmanship, mechanics, and metal-working, as was seen in the later Third Age. Gandalf was the servant of Manwë or Varda, but was a lover of the Gardens of Lórien, and so knew much of the hopes and dreams of Men and Elves. Radagast, servant of Yavanna, loved the things of nature, both Kelvar and Olvar. As each of these Istari learned from their Vala, so they acted in Middle-earth.
Demonic creatures of fire and shadow, Balrogs were fallen Maiar who were loyal to Morgoth. They participated in the wars of the First Age of Middle-earth but were mostly destroyed during the War of Wrath. By the Third Age, the only known remaining Balrog was "Durin's Bane," the Balrog of Moria, who was slain by Gandalf.
The Free Peoples of Middle-earth were those races that had never fallen under the sway of the evil spirits Morgoth or Sauron. Four races were traditionally regarded as the free peoples of Middle-earth: Elves, Men, Dwarves and Ents. Strictly speaking it was only the Men of the West who were Free People, particularly the descendants of the Dunedain of the Isle of Numenor, as most Men of the East and South of Middle-earth became servants of Morgoth and Sauron over the ages. The Ent Treebeard quotes lines from a traditional lay listing them 
- First came the four, the free peoples
- Eldest of all, the elf-children
- Dwarf the delver, dark are his houses
- Ent the earthborn, old as mountains
- Man the mortal, master of horses
After encountering the hobbits Merry and Pippin, he consents that hobbits are a fifth free people, adding a fifth line:
- Half-grown hobbits, the hole-dwellers
The race of Dwarves preferred to live in mountains and caves, settling in places such as Erebor (the Lonely Mountain), the Iron Hills, the Blue Mountains, and Moria (Khazad-dûm) in the Misty Mountains. Aulë the Smith created Dwarves; he also invented the Dwarven language, known as Khuzdul. Dwarves mined and worked precious metals throughout the mountains of Middle-earth. The seven different groups of Dwarf-folk originated in the locations where the Seven Fathers of the Dwarves first awoke before the First Age. The Petty-dwarves were smaller and more unsociable Dwarves of several houses, which had been banished[by whom?] in ancient times. They were aggressive, and fierce in battle.
The Elves, or Firstborn, were the first of Eru's Children to awaken. Born under the stars before the ascension of the Moon and the Sun, they retain a special love for light and an inner spirit endowed with unique gifts. They call themselves the Quendi, or "Speakers", for they were the first to utter words; and, even now, no race understands language and song like the Firstborn. Fair and fine featured, brilliant and proud, immortal and strong, tall and agile, they are the most blessed of the Free Peoples. They can see as well under moon or starlight as a man at the height of day. They cannot become sick or scarred, but if an Elf should die, from violence or losing the will to live from grief, their spirit goes to the halls of Mandos, and as they are bound to Arda and cannot leave until the world is broken and remade. Elven skill and agility is legendary: for instance, walking atop freshly fallen snow without leaving a trace of their passing. On a clear day they can see ten miles with perfect clarity and detail up to 100 miles. These gifts come at great cost, though: they are strongly bound to Fate (see Mandos) and hated by Morgoth. No other race has been blessed and cursed more than the Quendi.
The Quendi were sundered after the awakening and many sub-groups appeared. The First Sundering occurred when some left Middle-earth to live in the blessed realm of Valinor, while others stayed behind. This produced the Eldar, who accepted the call to come to Valinor, and the Avari who refused the great journey. Elves who stayed in Middle-earth and never saw the light of the trees became known as the Moriquendi or "Dark-elves". This did not imply that the Dark-elves were evil, they just never saw the light of the trees.
On the journey to Valinor, some of the Teleri ("Those who tarried") abandoned the main group and those of them who did not mingle with the Moriquendi became the Laiquendi (Green-elves), the Sindar (Grey-elves) and the Nandor. These elves of the great journey who remained in Middle-earth were then called the Úmanyar (The Unwilling). The Eldar who reached Valinor were eventually divided into three distinct groups: Vanyar, Noldor and Teleri. These three groups became known as the Calaquendi or "Light-elves" because they beheld the light of the Two Trees of Valinor. Later some of the Noldor went back to Middle-earth in their quest for the Silmarils, while the Vanyar remained in Valinor.
During the time of The Lord of the Rings, Men in Middle-earth were located in many locations, with the largest group of free men located in the countries of Gondor and Rohan. When the island of Númenor fell, only the Faithful escaped and founded the twin kingdoms of Gondor and Arnor. The Faithful were known in Middle-earth as the Dunedain, and as leaders of these kingdoms, they were able to lead the resistance to Sauron, and preserve the Men of the West as Free People . There were also free men at the village of Bree, at Esgaroth, in Drúadan Forest (home to "wild men" known as Drúedain or Woses), and in the icy regions of Forochel. Those who served evil powers, such as the men of Dunland, Rhûn, Harad, and Umbar, were not considered free men. Men bear the so-called Gift of Men, mortality.
Drúedain, or drughu, one of the earliest variety of men, lived in very little numbers, often in tribes. They were little folk, shorter than dwarves, yet taller than hobbits. They were known for their voodoo-like magic, their black eyes (which glow red when they are angry), and their ability to sit for hours and days on end without moving or blinking. They grew little hair, except that on their heads and sometimes small tufts on their chins. They were short and stout, and other men tended to dislike them due to their harsh, rough voices. Their laughter, however, was full of mirth. It is said that their skill of stonework rivaled the Dwarves'.
The Drughu were not evil. They were mortal enemies of orcs, defending the homes of their human neighbors with their own lives and with the aid of their magical Watch-Stones. The Elves of Beleriand developed a special fondness for them and valued their skill at fighting orcs.
Ents were an ancient race of tree-like creatures, having become like the trees that they shepherd. They were created by Yavanna and given life by Ilúvatar. By the Third Age, they were a dwindling race, having long ago lost their mates, the Entwives.
Close kin of the Ents, Huorns were animated trees that possessed sentience. They were said to have voices but could only be understood by the Ents, not by the other peoples of Middle-earth. It is unclear if Huorns were simply trees that became aware or Ents that became more "treeish" over time (both varieties were thought to exist). Huorns were found in Fangorn Forest and possibly the Old Forest near Buckland. It is thought that, perhaps, certain Elves would be able to understand the Huorns, for Legolas mentions that the Elves helped to wake up the trees.
Hobbits are a race of Middle-earth, also known as 'halflings' on account of their short stature, roughly half the size of men. They are characterized by curly hair on their heads and leathery feet that have furry insteps, for which they did not wear shoes. Many hobbits live in the Shire as well as Bree, and they once lived in the vales of the Anduin. They are fond of an unadventurous life of farming, eating, and socializing. There were three types of Hobbits: The Harfoots, the most numerous, were almost identical to the Hobbits as they are described in The Hobbit. The Stoors had an affinity for water, boats and swimming; the Fallohides were an adventurous people. The origin of hobbits is unclear, but of all the races they have the closest affinity to men, and in the Prologue to The Lord of the Rings Tolkien calls them relatives of men.
Enslaved peoples were those races that had fallen under the sway of the evil spirits Morgoth and Sauron, also known by the Free Peoples as 'Servants of the Enemy'. They included Orcs, Trolls and Men. The origin of Orcs and Trolls is unclear, but they were races that were taken by Morgoth and corrupted through sorcery into their final evil nature and appearance. Men were rarely corrupted by Morgoth or Sauron in the same way. Rather, their hearts and minds were corrupted by power and evil impulses, while they retained the physical appearance of men. Prolonged service to Sauron however, did turn the bearers of the Rings of Power from Men into the wraith-like Nazgûl. Those men who were the servants of Morgoth or Sauron were mostly from the east and south of Middle-earth.
Not all Men were on the side of good; the Men who lived in the east and south were under Sauron's dominion. They included the Haradrim or Southrons and the Black Númenóreans (and later the Corsairs of Umbar) who pledged their allegiance to Mordor, and many different Easterling peoples, such as the Balchoth, the Wainriders, and the Men of Khand, who attacked Gondor and Rohan on numerous occasions. The Men of Dunland served as agents to the traitorous wizard Saruman.
The Ringwraiths (also known as Nazgûl or Black Riders) were once great Men until they were given Rings of Power by Sauron. These gradually corrupted them until they became slaves of the Dark Lord's will. Clad in dark hooded cloaks and riding demonic steeds or flying "fell beasts," the Ringwraiths forever hunted for the One Ring to bring it back to their master.
Also known as ghosts or shades, they were spirits of Men unable to pass on to the afterlife. Spirits haunted various regions of Middle-earth, most notably the Dead Marshes and the Paths of the Dead, which were guarded by the Dead Men of Dunharrow. Ringwraiths and Barrow-wights are also counted among the Dead but are distinct in that they have physical form.
Orcs were a race first bred by Morgoth, which mostly lived in mountain caves and disliked sunlight. Many of them lived in the Misty Mountains while others lived in Mordor. They are also known as goblins. The Orcs were not created, since "evil cannot create, only corrupt" in Tolkien's philosophical perspective. One version of their origin, widely known in part due to the Peter Jackson's films, postulates that they were Elves who were corrupted and whose appearance was changed over time. However, Tolkien also wrote other accounts of their origin.
Sauron and Saruman the wizard bred strains of orcs called Uruk-hai. Although most orcs did not like the sun and could not bear to be in it, the Uruk-hai could stand daylight. Deformed Half-orcs also existed, crossbred from Men and Orcs.
Goblin is a word used interchangeably by Tolkien with the word Orc. Orcs are Goblins and vice versa. "Goblin" is sometimes colloquially used to refer to the smaller sub-races of Orcs native to the Misty Mountains, as in The Hobbit. See "Orcs" above for accounts of their origin.
Trolls were said to have been created by Morgoth "in mockery of" the Ents. They disliked the sun, and some types turned to stone if exposed to sunlight. Trolls dwelt in the Misty Mountains as well as in Mordor. Types of trolls included Stone-trolls, Cave-trolls, Hill-trolls, Mountain-trolls, Snow-trolls, and Troll-men of Far Harad. Sauron bred the Olog-hai, large, clever, and resistant to the sun.
Tom Bombadil is an enigma; it is unknown to which of the peoples of Middle-earth he belongs. He is clearly sentient and humanoid though. Unlike the other races, he is seemingly unaffected by the One Ring and appears to predate the Children of Ilúvatar (Elves and Men). As to the nature of Bombadil, Tolkien himself said that some things should remain mysterious in any mythology, "especially if an explanation actually exists."
Tom is also known as "The First", "Master Tom", "Old Tom", "Iarwain Ben-adar" (a Sindarin name meaning "The Oldest without a father"). The Noldor call him "Orald" meaning "Very Old", Dwarves call him "Forn" (meaning: The Ancient).
Spirits of nature tied to rivers and waterways. Only two are mentioned by Tolkien: Goldberry, the wife of Tom Bombadil, and her mother the River-woman. It is unknown whether these beings were unique, part of a larger race, or a form of Maiar.
Giants are referred to only a few times by Tolkien, leading some readers to debate whether they existed at all or if they were simply Ents or metaphorical descriptions of the power of nature. Stone-giants of the Misty Mountains are said to lob stones at Thorin and Company in The Hobbit.
- Essay on "The Istari" in Unfinished Tales.
- The History of Middle-earth, Vol. XII (The Peoples of Middle-earth), p. 384–385.
- The Lord of the Rings, The Two Towers, Book 3, Chapter IV 'Treebeard'
- Tolkien, J. R. R. (1977), Christopher Tolkien (ed.), The Silmarillion, Boston: Houghton Mifflin, The Sundering of the Elves, ISBN 0-395-25730-1
- Tolkien, J. R. R. (1954), The Fellowship of the Ring, The Lord of the Rings, Boston: Houghton Mifflin (published 1987), Foreword, ISBN 0-395-08254-4