What is the name of Mulder and Scully's son?

Mulder and Scully’s son is named William.

William is born during the eighth season of The X-Files, in the episode “Existence.” His birth follows a complicated storyline involving Scully’s infertility, in vitro fertilization, alien experimentation, and the uncertain circumstances of his conception. Both Mulder and Scully consistently regard him as their son.

The child is named William after Scully’s father, William Scully, and Mulder’s father, William Mulder. That shared family name gives the choice a personal connection to both parents. Scully later gives William up for adoption because she believes the conspiracies surrounding him place him in constant danger.

The character’s identity becomes even more complicated after adoption. He is known as Jackson Van De Kamp, but his birth name is William Scully III. Later revelations also complicate his biological parentage, yet “William” remains the canonical answer to this quiz question. The series’ ninth-season episode “William” focuses directly on his importance.