Describing Simpson, 61, as arrogant and ignorant, District Judge Jackie Glass said the evidence was overwhelming.
Simpson made an emotional appeal prior to sentencing at the Las Vegas court, saying he was "sorry" and "confused".
His accomplice, Clarence Stewart, was also sentenced to 15 years. Both men were convicted in October.
They were found guilty on 12 charges relating to the robbery and holding of the memorabilia dealers at Las Vegas' Palace Station hotel in September 2007.