Forrest Gump's son isn't actually his child - theory explained
Forrest Gump is a loving father to his son Forrest Gump Jr. (Haley Joel Osment), but is Jenny lying about his real parentage? Fan theory, explained.

According to one fan theory, Forrest Gump's son, played by Haley Joel Osment, might not be the biological son of Tom Hanks' titular genius. As a cornerstone of American storytelling, any challenge to the integrity of Forrest Gump feels like an attack on a family member. This is especially true for the idea of Forrest and Jenny, star-crossed lovers for most of the movie. Eventually, however, Jenny found her way back to Forrest, and the two reunited before parting again. It wasn't until she returned a second time with the baby that Forrest discovered he had a son and that he was about to lose a mate.
Forrest Gump's sweet relationship with Jr. is one of the film's most poignant moments, as it also accompanies Jenny's death - but is Jr. Gump really his son? Similar to other Forrest Gump fan theories, this one has plenty of evidence behind it, including a lack of confirmation that Gump and Jenny had sex, a rough timeline of events, and Jenny's behavior when she and Gump were reunited years later. At the same time, there are good reasons to believe that Jenny in Forrest Gump Telling the truth about her son's father. Here's a breakdown of theory, and why it might not be true.
Forrest Gump Never Showed Forrest Jr.'s Conception

The final scene in their relationship calls into question the biological relationship between Forrest Gump's son and the titular character. For one thing, the filmmakers didn't explicitly prove that Forrest Gump and Jenny's relationship was ever consummated. It is almost impossible for Forrest to have enough experience to understand such a process. Not only was he almost certainly a virgin, but he grew up in an area that lacked comprehensive sex education. While there's certainly precedent for using movie shorthand in place of actual sex scenes, the act is suggested if it's not confirmed here.
When Forrest Jr. Is Conceived According To The Movie

The timeline of Jenny's meeting with Forrest raises further questions about when Forrest's son became pregnant. When she initially returned to him, Forrest described how she fell asleep and slept for days - possibly suggesting she was pregnant. Maybe Jenny, after finding out she was pregnant, sought to break away from her previous lifestyle under the care of a trusted friend, where she could decide her next steps in a healthy environment, free from judgment.
Jenny apparently also bears The trauma experienced by young Jenny in the early scenes of Forrest Gump. Not long after, Jenny leaves Forrest—in keeping with her eternal free spirit, or rather, because she feels guilty about putting Forrest in this responsibility without his knowledge. When she returns to Forrest Gump off the beaten track again, she may just be preparing her son for the best possible life for his imminent death.
Debunking The Forrest Jr. Theory

A simple fact that complicates this theory is the child's name: Forrest Jr. It's hard to imagine that if she had had and raised a child with another father, she would have named him after Forrest (especially with the extension Jr.). Part of the time it's being portrayed like this, she probably doesn't know who Jr.'s father is, so decides to name him (and eventually hand him over to) the most responsible, invulnerable person she's ever known in her life. Oddly enough, Winston Groom's novel Forrest Gump ends with Jenny raising her and Forrest Gump's son, a man who doesn't Not smart, that's a secret shared by Forrest and Jenny.
Ultimately, this theory is rendered moot by the simple fact that Forrest accepted Jr. as his son without question. Like the rest of his life, Forrest is direct, honest, and unflinchingly kind in his dealings with Jenny's death and little Forrest's upbringing. At the end of the day, Forrest is the biological father of his son (family tree aside).
The Scrapped Sequel Would Have Explored Forrest Being A Parent

Forrest Gump 2 was originally planned to be based on Winston Groom's second book, Forrest Gump. In addition to charting Forrest Gump's life through major events in America in the '80s and '90s, the sequel will feature his older son and explore Forrest's journey as a parent. Given how heartwarming the ending scene with Gump and Gump was, it's likely to be well-received by viewers, and the couple will no doubt pull some shenanigans.
However, a sequel film never materialized, as screenwriter Eric Roth submitted his completed adaptation on September 10, 2001. After the next day's disastrous events, he, Hanks, and director Robert Zemeckis sat down and agreed that the Forrest Gump story wouldn't feel relevant anymore. Thus, the original Forrest Gump provided the only insight into what the beloved character was like as a father.
Forrest Jr's True Father Is One Of Many Forrest Gump Theories

Arguably darker than theory that Forrest Gump is dead, another speculates that he is under legal investigation for nefarious activities, and that he is telling his story to the townspeople to curry favor with them. Meanwhile, somewhat related to the Son of Gump theory, another, more innocuous theory wonders if Gump's story is true, or if he's just making it up to impress Jenny. As morbid, pessimistic, and even downright offensive to cinematic legacy as these theories may seem, they also make it clear that Forrest Gump remains one of the most influential films starring Tom Hanks, despite its It's been almost 30 years since its first release.