What is the name of Zoroaster's father according to traditional accounts?

According to traditional accounts, Zoroaster's father was named Pourushaspa.

Pourushaspa is the father named in Zoroastrian and later Iranian genealogical traditions. Zoroaster is usually identified as Zarathushtra Spitama, linking him to the Spitama family; his mother is traditionally called Dugdōw. The name Pourushaspa is often transliterated in slightly different ways, including Pourušaspa.

The family details come mainly from later tradition rather than from a full biography in the oldest Gathas, the hymns traditionally attributed to Zoroaster. That distinction matters because historians remain uncertain about many details of his life, including his dates and birthplace.

The other options are associated with different figures. Vishtaspa is traditionally Zoroaster's royal patron and an early convert, while Jamasp is associated with Vishtaspa's court and later Zoroastrian tradition. Thus Pourushaspa is the standard answer to this genealogy question.