The 50-year-old Motley Crue singer got out of the Clark County Detention Center on Friday, the Las Vegas Sun reported.
Neil pleaded guilty in January to driving drunk near the Las Vegas Strip in the summer of 2010.
He was sentenced to 15 days in jail and 15 days on house arrest under a plea deal that spared him a trial. He was also fined $585.
Neil could have faced up to six months in jail if convicted.
Las Vegas police said he was stopped in his black Lamborghini sports car June 27 after leaving the Las Vegas Hilton resort.
The Associated Press contributed to this report.
