According to the terms of the sentence delivered Friday, the celebrity must spend 45 days behind bars for driving with a suspended license.
After the ruling, Hilton told members of the media that she told the truth during her hearing, and that she feels the punishment is cruel.
If the appeal is rejected, the Simple Life star will begin serving her time in a Los Angeles prison on June 5.
Paris Hilton was stopped on January 22 for driving while intoxicated. On February 27, she was again stopped for the same offence, and her license was suspended.