In Welsh mythology, Teyrnon or Teirnon was the foster father of Pryderi.
The child appeared in the court of King Teyrnon, whose mares had just given birth but the foals had disappeared. Teirnon watched his stables and saw a mysterious beast coming to take the foal; Tiernon stopped the beast and found the child outside the stable. He and his wife adopted him. The child grew to adulthood in only seven years and was given the foal which had led Teyrnon to the stable. Teyrnon realized who the child was and returned him to Pwyll and Rhiannon, his parents, who named him Pryderi (worry).
