Some pretty huge claims have been made over the years though despite KJ's best efforts, and it has been suggested that O.J Simpson was her biological father instead.
But reports that O.J. Simpson, a close friend and client of Robert's, is Khloe's father have been circulating since at least 2012.
Fans of KUWTK will remember that Khlo-money even had doubts at one point herself over her parents, forcing mama Kris Jenner to step in and shut down the rumours with a DNA test.
He added: "I would be proud ... but trust me, I had nothing to do with it". However, the former National Football League running back - who played with the Buffalo Bills and San Francisco 49ers - still spent time behind bars from 2008 through 2017 following a conviction for armed robbery stemming from a 2007 incident in Las Vegas.
The parolee says, "Well, for Bob, God bless his soul, yeah".
Now TMZ put the question to the No. 1 paternity suspect - outside of the late Robert Kardashian.
"But I don't know for me".
OJ Simpson has finally denied he is Khloe Kardashian's father after decades of speculation. Those rumors intensified in 2013 after Robert Sr.'s wife said he told her that Khloe was not his real daughter before dying in 2003, In Touch Weekly reported. I was like, 'Listen, you can talk about me and my sisters all you f**king want.
"If you f**ked other people during the same time and you do not know, go on Maury!"
Robert's second and third wives have also claimed that the late-Kardashian told them both that Khloe was not his child.
Simpson was granted parole in July 2017, and he was officially released in October 2017.