In Norse and Anglo-Saxon mythology, a jötunn or, in the normalised scholarly spelling of Old Norse, jǫtunn (//; plural jötnar/jǫtnar) is a type of entity contrasted with gods (Aesir and Vanir) and other non-human figures, such as dwarfs and elves. The entities are themselves ambiguously defined, variously referred to by several other terms, including risi, thurs and troll. The jötnar predominantly dwell in Jötunheimr, however they are sometimes referred to as living in specific geographical locations such as Ægir on Læsø. 
Although the term giant is sometimes used to gloss the word jötunn and its apparent synonyms in some translations and academic texts, jötnar are not necessarily notably large and may be described as exceedingly beautiful or as alarmingly grotesque. Some deities, such as Skaði and Gerðr, who are married to Njörðr and Freyr respectively, are themselves described as jötnar. Reference to Skaði's vés in Lokasenna and toponyms such as Skedevi in Sweden suggests that despite being a jötunn, Skaði was worshipped in Old Norse religion.  Furthermore, various well-attested deities, such as Odin and Thor, are descendants of the jötnar. This supports the idea that the distinction between gods and jötnar is not clearly defined and they should be seen as different cultures or peoples rather than different types of being. In later Scandinavian folklore, the ambiguity surrounding the entities gives way to negative portrayals. Belief in jötnar also survived in English folklore as ettins.
Old Norse jötunn (also jǫtunn) and Old English eoten developed from the Proto-Germanic masculine noun *etunaz. Philologist Vladimir Orel says that semantic connections between *etunaz with Proto-Germanic *etanan makes a relation between the two nouns likely. Proto-Germanic *etanan is reconstructed from Old Norse etall "consuming", Old English etol "voracious, gluttonous", and Old High German filu-ezzal "greedy". Old Norse risi and Old High German riso derive from the Proto-Germanic masculine noun *wrisjon. Orel observes that the Old Saxon adjective wrisi-līke "enormous" is likely also connected.
Old Norse þurs, Old English ðyrs, and Old High German duris "devil, evil spirit" derive from the Proto-Germanic masculine noun *þur(i)saz, itself derived form Proto-Germanic *þurēnan, which is etymologically connected to Sanskrit turá- "strong, powerful, rich". Several terms are used specifically to refer to female entities that fall into this category, including íviðja (plural íviðjur) and gýgr (plural gýgjar).
Norse myth traces the origin of the jötnar to the proto-being Ymir, a result of growth or sexless reproduction from the entity's body. Ymir is later killed, his body is dismembered to create the world, and the jötnar survive this event by way of sailing through a flood of Ymir's blood. The drowning of the jötnar in a flood is pictured on the hilt of the jötunn sword used by Beowulf to slay Grendel's mother. 
The jötnar are frequently attested throughout the Old Norse record. For example, in a stanza of Völuspá hin skamma (found in the poem "Hyndluljóð"), a variety of origins are provided: völvas are descended from Viðòlfr, all seers from Vilmeiðr, all charm-workers from Svarthöfði, and all jötnar descend from Ymir.
The Icelandic and Norwegian rune poems name the rune þ as thurs and state that thursar cause strife to women.
In the Old English poem Beowulf, Grendel, and by association potentially Grendel's mother, is a jötunn and is referred to as a þyrse (thurs). Maxims II states that a thurs lives in alone in fens, consistent with Beowulf.
In popular culture
- Jötunn appear with human disguises in the third season of The Librarians.
- The Jutul family are jötunn masquerading as humans in the Norwegian-language drama Ragnarok.
- The Jötunn influenced in the creation the mute giants named "Titans" from the Attack on Titan manga and anime series.
- A jötunn appears in the 2017 film The Ritual, depicted as a bastard son of Loki and worshiped as a god.
- Jotunn's Wrath exists as a weapon granting spell enhancements, appearing in the popular mythological MOBA video game, SMITE.
- A depiction of jötunn as a weapon appears in Bungie's video game Destiny 2.
- Jötnar appear in the episode 356 of the manga Berserk as part of the astral races that appeared after the merging of the physical world and astral world, being defeated by the new Band of the Falcon in the following episode.
- The jötnar are frequently mentioned in the 2018 video game God of War.
- Jötnar are frequently depicted in the Danish comic series Valhalla, created by Henning Kure and Peter Madsen, based on the Norse myths and starring the gods.
- Jötnar are an enemy faced in the 2020 video game Assassin's Creed: Valhalla.
- Jötnar are found in the 2020 adventure game Röki where they appear as giant animal guardians.
- Jötun are a race found in the fifth book of Fire Emblem Heroes.
- Jötunn Winter is the name of the third battle pass of Brawlhalla.
- Asura – a comparable class of deities in Indian mythology
- Div – a comparable class of giants in Islamic-Persian lore
- Giants (Marvel Comics)
- Giant (Dungeons & Dragons)
- List of jötnar in Norse mythology
- Titan – a comparable class of deities in Greek mythology
- "Jotun". Random House Webster's Unabridged Dictionary.
- Heide E Contradictory cosmology in Old Norse myth and religion – but still a system? Maal og minne Available at: https://www.academia.edu/7454838/Contradictory_cosmology_in_Old_Norse_myth_and_religion_but_still_a_system [Accessed June 14, 2021]
- Some translators of the Poetic Edda do not render the word jötunn to giant. For example, in the Foreword to Jeramy Dodds's translation of the Poetic Edda, Terry Gunnell says that jötnar is "sometimes wrongly translated as 'giants'" and instead uses jötunns. (Dodds 2014:9).
- Blótgyðjur, Goðar, Mimi, Incest, and Wagons: Oral Memories of the | Terry Gunnell - Academia.edu Available at: https://www.academia.edu/36066115/Blótgyðjur_Goðar_Mimi_Incest_and_Wagons_Oral_Memories_of_the [Accessed June 15, 2021]
- Orel (2003:86).
- Orel (2003:472).
- Orel (2003:429–430).
- "Ettin | Origin and meaning of ettin by Online Etymology Dictionary".
- Bellows (1923:229) and Thorpe (1866:111).
- "Maxims II (Old English)". Sacred Texts.
- "Maxims II (Modern English)". Old English Poetry Project, Rutgers.
- Bellows, Henry Adams (trans.) (1936). The Poetic Edda. Princeton University Press. New York: The American-Scandinavian Foundation.
- Dodds, Jeramy (trans.) (2014). The Poetic Edda. Coach House Books. ISBN 978-1552452967.
- Orel, Vladimir (2003). A Handbook of Germanic Etymology. Brill. ISBN 9004128751
- Thorpe, Benjamin (trans.) (1866). Edda Sæmundar Hinns Frôða: The Edda of Sæmund the Learned. Part I. London: Trübner & Co.
- Media related to Jötnar at Wikimedia Commons