The ruling came 13 years to the day after Simpson was acquitted of brutally murdering his ex-wife Nicole and her friend Ron Goldman.
After a three-week trial, a Las Vegas jury deliberated for more than 13 hours on Friday on charges against Simpson and a friend arising from an incident at the Palace Station casino in September last year.
Simpson showed no emotion as he and co-defendant Clarence Stewart were found guilty on all charges, which could see both men facing a maximum life sentence.
Shortly after the verdicts were read out just before 11:00 pm (0600 GMT) local time, Judge Jackie Glass denied a request for Simpson to be released on bail and he was led away in handcuffs.
The 61-year-old former American football hero was accused of storming into a hotel room with a gang of gun-toting cohorts and seizing sports memorabilia from two dealers worth thousands of dollars.
He will sentenced on December 5.