According to Matthew's genealogy, who was the father of Joseph, husband of Mary?

Answer: Jacob

Eleazar was the father of Matthan, Matthan the father of Jacob, and Jacob the father of Joseph, the husband of Mary.

“Eliud was the father of Eleazar, Eleazar the father of Matthan, Matthan the father of Jacob, and Jacob the father of Joseph, the husband of Mary, of whom was born Jesus, who is called Christ.”— Matthew 1:15-16 (BSB)