He could be seen responding "OK" as he left, wearing a ball cap, denim jacket, jeans and white tennis shoes.
His five years of parole supervision could be reduced with credits for good behaviour.
According to reports, he walked out of the Lovelock Correctional Institute at 12:08 a.m. local time on Sunday, the Nevada Department of Corrections said.
"Our biggest concern was our safety and the public's safety and not wanting anybody, paparazzi, to follow him", shet said.
- February 1997: After a trial in a civil suit filed by the victims' families, a jury finds Simpson liable for the deaths and orders him to pay survivors $33.5 million.
Bondi released a letter she sent Friday to state Department of Corrections Director Julie Jones, saying that Florida taxpayers should not "foot the bill" for overseeing Simpson's parole.
"While we respect the Nevada Parole Board's decision to release Simpson, it's still hard for us knowing he will be a free man again", the Goldmans said.More news: Tim Cook delivers message, people queue up on Day 1
Nor has the state of California, where Simpson's sister, Shirley Baker, and oldest daughter, Arnelle, live.
Simpson's Malcolm LaVergne said there's "no doubt" Simpson is going to Florida. LaVergne said he will begin pressing for answers if Simpson is not free by October 8.
According to a Nevada prison official, former National Football League (NFL) star and film actor, O.J. Simpson has been released after a nine-year sentence for armed robbery.
Simpson's living arrangements outside prison have not been made public.
Florida Attorney General Pam Bondi said earlier in the week that Simpson was not welcome in Florida. It is believed that Simpson was released late at night in order to avoid a media circus.
Although Simpson, 70, formerly lived in Kendall, one of his longtime friends told USA Today before the hearing Simpson might come to live with him in Naples.
In the late 1990s, Simpson also moved to Florida, where "under the state's homestead exemption, forced sale of residences can be blocked", Sports Illustrated explained.
O.J. Simpson smiles at his parole hearing in Nevada last July.