Simpson's family says he passed away in Las Vegas on Wednesday after a battle with cancer.
Simpson was acquitted of the brutal murders of his ex-wife Nicole Brown Simpson and her friend Ron Goldman in June 1994.
In 2008, he was found guilty on robbery and kidnapping charges and sentenced to 33 years in prison, but was released on parole in 2017.
As a star running back, Simpson played in the NFL for 11 seasons, for the Buffalo Bills and San Francisco 49ers.
He was a national icon in his football retirement, starring in movies, TV shows and commercials.
He went on to become a broadcaster for ABC and NBC, before he was accused of the double-murder.
OJ Simpson has five adult children from two marriages.