Maria de Yriarte

María de Yriarte (also recorded Iriarte and Yriart; –1610) was a Basque woman accused of witchcraft and vampirism during the Basque witch trials. She died in prison before being tried and burned in effigy at the stake in Logroño.

Yriarte was the daughter of Graciana de Barrenechea and Juanes (or Joanes) de Yriarte, a shepherd. She had two sisters, including fellow accused witch Estevanía; the family lived in and around Zugarramurdi. When questioned on accusations of witchcraft, the accounts of Yriarte, her mother, and her brother-in-law Juanes (or Joanes) de Goyburu provided the basis for further accusations of creating and using toad poison. This is perhaps the earliest association of a toad being the familiar of a witch.

Like her sister and mother, Yriarte died in prison before the Logroño auto-da-fé, but was still tried and her effigy was burned. According to El Diario Vasco, she was 40 years old when she died. Records of the 1610 auto-da-fé include stories of the accused witches' sexual relations with the devil: for intercourse "in both parts", which left her bloodied and in pain.

She was posthumously absolved of any crime. As of 2025, her house in Zugarramurdi, like her mother's, is still standing. Known as the Iriartea, it has been converted into a country house.