The 24-year old Dutchman pleaded guilty on Wednesday to all charges related to the killing of Stephany Flores.
The court also ordered him to pay $75,000 in reparations to the family to the 21-year-old victim. The prosecution had sought a 30-year sentence for first-degree murder and theft.
Van der Sloot is the prime suspect in the unsolved disappearance of American teen Natalee Holloway.
She disappeared in Aruba in 2005 and was last seen leaving a nightclub with Van der Sloot. He was arrested twice in the case, but never charged. A judge signed an order Thursday declaring Holloway legally dead.
Flores was killed exactly five years after Holloway's disappearance.