In March, Chaney, 35, pleaded guilty to nine felony counts in federal court, including wiretapping, unauthorized access to a protected computer and damaging a protected computer. The prosecution dropped a charge of aggravated identity theft in exchange for the guilty plea.
In total, Chaney was found to have cyber-stalked 60 victims.
The judge said Monday that Chaney was likely to continue with stalking behavior after his release from prison.
"The defendant does not appear to understand the seriousness of his conduct," the judge said in sentencing Chaney.
Chaney apologized in court Monday.
Johansson sent a pre-taped message for the judge and actress Renee Olstead also gave an impact statement on the damage Chaney had done. Aguilera has also made a statement about the invasion of her privacy.
Chaney will be placed on three years of supervised probation when he is released and will have to notify officials of his online accounts. But the judge feared that wouldn't be enough and said he wished he could sentence Chaney to lifetime supervision.
The judge also ordered Chaney to pay restitution to the victims, it was confirmed by On The Red Carpet. Chaney is to pay $5,000 each to Olstead and Aguilera and $66,179.46 to Johansson. However, the judge recognized that it is unlikely Chaney will ever pay all the restitution ordered.
Prosecutors said Chaney illegally accessed the email accounts of more than 50 people in the entertainment industry between November 2010 and October 2011. Aguilera, Mila Kunis and Johansson agreed to have their identities made public with the hope the move would provide awareness about online intrusion.
Chaney was arrested in October 2011 as part of a yearlong investigation of celebrity hacking that authorities dubbed "Operation Hackerazzi." Chaney's computer hard drive contained numerous private celebrity photos and a document that compiled their extensive personal data, according to a search warrant.
He continued to pursue his victims after the FBI seized his computer, a factor Otero said warranted a harsher penalty.
The Associated Press contributed to this report.