I’ve recently started watching the X-Files again because it’s on every single night and I haven’t been sleeping too good. A friend of mine and I started talking about it, and neither one of us can remember if he definitely is or if he only claimed he was or what? It’s all very confusing. Anybody got the straight dope?
Yes, he’s Mulder’s father. While the smoking man made claims of this throughout the series, the definitive proof for this came from a DNA test of Jeffrey Spender in “William,” one of the very last season nine episodes: Mulder and Jeffrey’s DNA matched so closely that they had to be half-brothers.
Now, a question no one knows the answer to is this: is he Samantha’s father too, or is she Bill Mulder’s biological daughter? It’s a fun question for fics, since they never said either way on the show.
Thanks muchly!
I was all set to post my “no he’s not but he used to work with Mulder’s dad back in the day” and elfkin shows up with the science. I appreciate your knowledge but choose to continue to pretend that the last few seasons of the X-Files never happened.
WHat are you talking about? The show was cancelled without an ending following David Duchovney’s decision to leave. 
Um, Mulder was already born before Spender became Smoking Man or was aware of the Mulder family (Remember the ep. where Smoking Man is eavesdropping on a Lone Gunmaen debriefing about his career?). I like to think that Papa Mulder and Mama Spender got their freak on together at some point.
In the episode you’re talking about- “Musings of the cigarette smoking man”- Bill Mulder shows CSM a picture of his wife and baby. A little later on the show that CSM has the same picture himself, suggesting that while he might not know Bill well, he certainly knew Teena before that time.
Of course, they never say how long they were in the army, or if Bill and CSM knew each other before then, or how long they were supposed to have known each other when the picture was flashed…