Actor Jodie Sweetin clarifies how Joey Gladstone is related to the Tanners in Full House. The ABC sitcom didn't start as an instant hit. Over time, however, it became a cult classic, with its base further expanding thanks to Netflix's spin-off sequel, Fuller House. Despite the Tanners being on the small screen for a total of 13 seasons, there are still a lot of misconceptions about them, including Joey's true relationship with Danny's family.
In How Rude, Tanneritos (a Full House rewatch podcast launched three years after Fuller House ended on Netflix), Sweetin discusses the common misconception that Joey is DJ, Stephanie, and Michelle's uncle. Read her full quote below:
He's not an uncle. I'm gonna debate this fact, because people always say, 'Oh, what about Uncle Joey?' And I'm the first to [say], 'Like, actually, he's not an uncle.' And we never called him 'Uncle Joey.'
The events of Full House were kicked off after Danny was suddenly widowed and left to raise three young kids on his own. After getting some help from his own mom, the single dad got long-term assistance from his brother-in-law, Jesse, and college friend, Joey. Sweetin is correct that there was never any mention of Joey being related to them. He and Danny were just excellent friends, hence the living arrangement they agreed on. In any case, Joey moving in with the Tanners wasn't just purely because he wanted to help Danny. As a struggling comedian, staying with the family immensely helped his finances.
Because of the unclear ties of the character to the Tanners, Joey is often the subject of many theories. One of the biggest ones claims that Joey is actually the father of the Full House kids. This is solely based on him being blonde, like DJ, Stephanie, and Michelle. Admittedly, the argument is weak because the show never delved deep into the character's origins separate from his existing relationship with Danny, so it's easy to come up with various hypotheses about him. In addition, while Full House put him at the center of its storytelling at times, he didn't have a clear personal arc as Jesse did.
Just because he wasn't blood-related doesn't mean that Joey wasn't treated like family, however. The character was proof of Full House's concept of found family. It featured a non-traditional household with three men raising three young girls. If anything, the fact that Joey could devote so much of his time and effort to raising Danny's kids despite not being related to them makes him more lovable.