The robbery was caught on tape, showing Anthony Carleo wearing a motorcycle helmet and carrying a gun as he ran out of the casino.
Carleo apologized at his sentencing for "all the chaos I've caused."
"I know my actions were reckless," Carleo said. "... I'm extremely sorry for everything I've done. I owe my mother and father an apology. I'm sorry, your honor."
Judge Michelle Leavitt sentenced Carleo to at least 3 years in prison but no more than 11 years, unless he's paroled when he's first eligible in 2014. Leavitt also gave him credit for the nearly seven months he has served in jail.
The judge didn't make a decision on whether Carleo will have to repay $1.5 million in chips that were stolen, but most have been recovered.
Prosecutor Chris Owens, who argued for a stiffer sentence, said that when Carleo was arrested, authorities discovered written plans by him to rob Caesars Palace, the iconic Sin City casino that sits just north of the Bellagio.
Carleo is expected to be sentenced Thursday for another robbery at the Suncoast Hotel & Casino in northwest Las Vegas just days before the Bellagio heist. Authorities have said it played out like a dress rehearsal for the Bellagio theft.
The Associated Press contributed to this report.