Simpson, 70, won his freedom from a Nevada parole board in July after nine years behind bars, at a hearing that did not take into account his 1990s trial for the murder of his ex-wife Nicole Brown Simpson and a friend, Ron Goldman.
He reportedly left prison shortly after midnight local time.
Simpson, a former pro football star turned actor and TV pitchman, was found not guilty in 1995 following his sensational, 13-month trial in Los Angeles, which was televised live daily, transfixing much of the country.
A civil court jury subsequently found him liable for the deaths and ordered him to pay $33.5 million in damages to the victims' families, a judgment that remains largely unpaid.
Simpson's ultimate destination remains unclear. He told parole board members he hopes to move to Florida, where he has friends and family, a plan that must be approved by probation authorities there.
O.J. Simpson (C) attends a parole hearing at Lovelock Correctional Center July 20, 2017 in Lovelock, Nevada
Image credit: Getty Images
Florida corrections officials say they had not received a parole transfer request for Simpson and had not been contacted by their counterparts in Nevada.
Simpson is a native of California, born in San Francisco, and played his final years as a pro football player for that city's team, the 49ers. He lived in Los Angeles at the time of the murders.
But California corrections officials say he has not filed papers to live in that state either.
At his parole hearing, Simpson, known during his football career as the “Juice”, said he was ready to spend time with his children and friends outside prison and could handle the public attention he would get.
Among reasons the commissioners gave for their decision was that Simpson had complied with prison rules during his incarceration, had no prior criminal convictions and posed a minimal safety risk to the public.
Simpson won the Heisman Trophy, the award for the top college football player, in 1968 while attending the University of Southern California. He played more than a decade in the National Football League, becoming the first player to rush for more than 2,000 yards in a season.