Realistically, Judith’s father is probably Shane

AMC
The case for Shane being Judith’s father is simple: Rick spent several weeks at the hospital in a coma. During those weeks the apocalypse happened, and at some point Lori and Shane started hooking up. The exact timeline is intentionally left fuzzy by the show, but the scenes we do get of Lori and Shane in the early episodes imply that they’ve been having unprotected sex on a regular basis.
Advertisement
After Rick and Lori reunite, they have sex at least once before Lori finds out she’s pregnant, but they quickly start having marital troubles as Rick finds out everything that’s happened. To put it simply: there were many more opportunities for Shane to impregnate Lori than for Rick, although it is technically possible that it was Rick who did the deed.
Because DNA tests are hard to find in the apocalypse, both Lori and Rick seem content to just assume Rick’s the father and not really dwell on it. Shane, however, fully believes the baby is his, and his possessiveness towards Lori and her unborn child is a big part of what turns him increasingly vindictive and unstable throughout “The Walking Dead” season 2. If Rick hadn’t killed him in “Better Angels,” it’s clear that Shane would’ve kept thinking of the baby as his own, and would’ve kept feuding with Rick because of this.
Advertisement
After the time jump, fans were observing Judith closely for any signs of Shane-esque behavior. All she needed to do was rub the back of her head and the jig would be up, but instead she act more like how you’d expect the daughter of Rick Grimes to behave. Physically, she doesn’t seem to share many similarities with either father. (Honestly, she doesn’t even look much like Lori either.) It seems that when it comes to the question of Judith’s biological father, the answer is entirely up to fans to decide.
But who does Rick think the father is?

AMC
A notable piece of evidence in the “Shane’s the father” camp, and one I think fans put too much stock in, is a season 7 scene where Rick straight up says, “I know Judith isn’t mine. I know it. I love her, she’s my daughter but she isn’t mine. I had to accept that.”
Advertisement
Some fans take this as confirmation of Judith’s parenthood, but others interpret it as Rick simply explaining his decision-making process. He “accepts” that Judith is Shane’s biological daughter so that he doesn’t have to constant wonder what the truth is. If he can accept the worst-case scenario and still love Judith, then he knows his relationship with her will be fine no matter what. This ties into the argument Rick’s making to Michonne throughout the scene: that they (the Alexandrians at war with Negan) need to accept the worst possible outcome of a situation from the start, so that it won’t nag at them and cloud their judgment going forward.
But even if you do take Rick’s words at face value here, the takeaway for Judith is still the same. In all the ways that count, she’s Rick’s daughter. He’s the one who raised her (for those first few years at least), and it’s his and Michonne’s values she grew up learning. Even if Judith got her DNA tested and found conclusive evidence that she wasn’t Rick’s daughter, hopefully she’d know not to pay it any mind.
Advertisement