Thor’s family tree is headed by Odin and Jord (or Fjörgyn), making him a half-giant Aesir god, and it branches through his wife Sif, his children, and his infamous brother Loki. The clearest ancient sources are the Poetic Edda and Prose Edda, though they sometimes disagree on details, so any family tree is a composite of those texts.
Parents: Odin and Jord
Thor is the son of Odin, the chief of the Aesir, and a giantess named Jord (meaning “earth”) in most sources. The Prose Edda by Snorri Sturluson states: “Thor is the son of Odin and Jord.” Jord is also called Fjörgyn in the Poetic Edda (e.g., in Hárbarðsljóð and Vafþrúðnismál), which may be an alternate name or a separate giantess. Some scholars treat Fjörgyn as a distinct earth-goddess, but the texts use the names interchangeably for Thor’s mother.
Odin had many children by different mothers, so Thor’s half-siblings include Baldr (son of Frigg), Víðarr (son of the giantess Gríðr), and Váli (son of Rindr). In Lokasenna, Loki taunts Thor about his mother being a giantess, which confirms that Thor’s maternal ancestry was well known and sometimes used as an insult.
Wife and Children
Thor’s wife is Sif, a goddess associated with grain and fertility, famous for her golden hair. In the Prose Edda, Loki cuts off Sif’s hair as a prank, and Thor forces him to commission golden replacements from the dwarves—this story explains why Sif is always depicted with gold hair. Sif and Thor had a daughter named Þrúðr (meaning “strength”), who is mentioned in Alvíssmál as the object of the dwarf Alvíss’s unwanted marriage proposal. Thor outwits the dwarf by keeping him talking until sunrise, turning him to stone.
Thor also had sons, but their mothers are not always named. The Prose Edda lists Móði (“courage”) and Magni (“strength”) as Thor’s sons. Magni is specifically said to be the son of Thor and the giantess Járnsaxa, not Sif. This is a key detail: Thor had at least one child outside his marriage, and that child was considered legitimate enough to inherit his strength. In Gylfaginning, after Thor kills the giant Hrungnir, Magni (only three years old) lifts the giant’s leg off Thor, and Odin praises him. Móði’s mother is not stated in any source; he is simply called “son of Thor.”
In the Prose Edda, it is prophesied that Móði and Magni will survive Ragnarök and inherit Thor’s hammer Mjölnir. This makes them the direct continuation of Thor’s line after the end of the world.
Loki: Brother or Not?
Loki is not Thor’s biological brother in any surviving text. In Lokasenna, Loki says he and Odin swore blood-brotherhood, making Loki Odin’s sworn brother—which would make Loki Thor’s uncle by oath, not his sibling. However, the Prose Edda calls Loki “Thor’s brother” in a few passages, and modern popular culture (like the Marvel comics) has cemented the idea of them as brothers. The ancient sources are inconsistent: Loki is sometimes called Odin’s blood-brother, sometimes a companion, and sometimes a giant who lives among the Aesir. For a family tree, the safest statement is that Loki is Thor’s companion and occasional ally, but not a biological brother in the Eddas.
Children of Loki and Their Connection to Thor
Loki’s children are not Thor’s children, but they are part of the same mythological family drama. Loki fathered the wolf Fenrir, the serpent Jörmungandr, and the half-dead Hel with the giantess Angrboða. Thor has direct conflict with two of them: he wrestles with Jörmungandr during a fishing trip (in Hymiskviða and Gylfaginning), and at Ragnarök he kills the serpent but dies from its venom. Fenrir is destined to kill Odin, not Thor, but Fenrir’s son Sköll swallows the sun. Loki also fathered Sleipnir, Odin’s eight-legged horse, with the stallion Svaðilfari—an episode that shows Loki’s shape-shifting abilities.
These connections matter because Thor’s death at Ragnarök is directly tied to Loki’s offspring. The family tree thus extends beyond blood to include the figures Thor fights and ultimately dies alongside.
Other Relatives and Half-Siblings
Thor’s half-siblings on Odin’s side include:
- Baldr – the beloved god whose death triggers Ragnarök; son of Odin and Frigg.
- Höðr – the blind god who kills Baldr with a mistletoe spear, also son of Odin and Frigg.
- Víðarr – the silent god who avenges Odin by tearing Fenrir’s jaw at Ragnarök; son of Odin and the giantess Gríðr.
- Váli – son of Odin and Rindr, born specifically to avenge Baldr’s death.
- Hermóðr – a son of Odin who rides to Hel to try to bring Baldr back; appears in the Prose Edda.
Thor’s mother Jord is sometimes personified as the earth itself, which makes Thor a “son of the earth” in a literal sense. This is why he is often called “Earth’s son” in kennings (poetic circumlocutions).
Family Tree in Practice: A Simplified Chart
If you want a quick visual, here is the most widely accepted tree based on the Eddas:
- Odin (father) + Jord/Fjörgyn (mother) → Thor
- Thor + Sif → Þrúðr (daughter)
- Thor + Járnsaxa (giantess) → Magni (son)
- Thor + unknown mother → Móði (son)
- Odin’s other children (Baldr, Höðr, Víðarr, Váli, Hermóðr) are Thor’s half-siblings.
Note that some medieval texts, like the Flateyjarbók, add extra daughters or sons, but these are not consistent. For example, Þrymskviða mentions a daughter of Sif and Thor named “Lóru” in some manuscripts, but this is a late addition and not considered canonical.
Common Misconceptions
One frequent error is calling Loki Thor’s brother without qualification. As noted, the Eddas do not support a biological brotherhood. Another misconception is that Sif is Thor’s only wife; he clearly had a relationship with Járnsaxa, and possibly others. Also, some modern retellings make Thor the son of Frigg, but Frigg is Odin’s wife and mother of Baldr, not Thor. The Prose Edda explicitly says Thor’s mother is Jord.
Another misconception is that Thor’s hammer Mjölnir was passed down through his family. In fact, Mjölnir was made by dwarves (the sons of Ivaldi) and given to Thor by Loki as compensation for cutting Sif’s hair. It is not an heirloom; it is a gift, and it returns to Thor’s hand after being thrown.
Frequently Asked Questions
Who is Thor’s mother?
Thor’s mother is Jord, a giantess who personifies the earth. In the Prose Edda, she is called “Jord” and also “Fjörgyn” in the Poetic Edda. She is not Frigg, who is Odin’s wife and mother of Baldr.
Does Thor have any children in Norse mythology?
Yes. With Sif he has a daughter Þrúðr. With the giantess Járnsaxa he has a son Magni. He also has a son Móði, whose mother is unknown. Móði and Magni survive Ragnarök and inherit Mjölnir.
Is Loki Thor’s brother?
In the ancient sources, no. Loki is Odin’s blood-brother in Lokasenna, making him Thor’s uncle by oath. The Prose Edda occasionally calls Loki “Thor’s brother” in a loose sense, but this is not a biological relationship. The idea of them as brothers comes from Marvel comics.
Who is Thor’s wife?
Thor’s wife is Sif, a goddess of grain and fertility. She is famous for her golden hair, which Loki cut off and replaced with gold made by dwarves. Thor also had a relationship with the giantess Járnsaxa, who bore his son Magni.
Will Thor’s family survive Ragnarök?
Thor dies at Ragnarök after killing Jörmungandr and taking nine steps before falling dead from the serpent’s venom. His sons Móði and Magni survive and inherit Mjölnir. His daughter Þrúðr is not mentioned in Ragnarök accounts, so her fate is unknown.
Why is Thor called “son of Earth”?
Because his mother Jord is the earth personified. In skaldic poetry, kennings like “son of Earth” or “Jord’s son” are common for Thor, emphasizing his giantess ancestry and his role as a fertility and thunder god.
Related
- Chloris in Greek Mythology: Goddess of Flowers
- Mami in Mesopotamian Mythology: Goddess of Birth
- Mors in Roman Mythology: Death Personified
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