His father was a wizard & his mother was a muggle. After they were both killed by Voldemort, Harry was brought up by his Aunt Petunia (his mother's sister) & Uncle Vernon, who were both muggles.
Lily Potter - Harry's mum - was a witch born to muggle parents. Lily's sister, the awful Aunt Petunia, is somehow responsible for "topping up" Harry's protection against Lord V. James Potter was a wizard. Anyone think Sirius isn't dead?
No. Both of his parents are wizards and witches. In a couple of the books, they talk about James meeting Lilly at Hogwarts. How could muggles meet at Hogwarts when muggles can't even see Hogwarts? But, his grandparents were (on Lilly's side, I don't know anything about Jame's side of the family.
And I hope Siruis isn't dead. I love Siruis. I cried when he died.