"I am ready to face the consequences of violating probation," she said in a statement released by her lawyer. "During the past few weeks I have had a lot of time to think and have come to realize I made some mistakes.
"This is an important point in my life and I need to take responsibility for my actions. In the future, I plan on taking more of an active role in the decisions I make. I want to thank my family, friends and fans for their continued support. Although I am scared, I am ready to begin my jail sentence."
Hilton's attorney, Richard A. Hutton, said in a press release that the 26-year-old heiress had "turned herself in" to begin serving the sentence at the Century Regional Detention Facility in Lynwood, south of Los Angeles.
She was booked into the jail at 11:38 p.m., according to the Los Angeles County Sheriff's Department's Web site, after days of partying and just hours after attending the MTV Movie Awards.
Hilton actually surrendered at the downtown L.A. Men's Central Jail at 11:15 p.m. and was transported to Lynwood, according to TMZ.com, which first reported her surrender.
The procedure at the Lynwood jail required her to surrender all her possessions and then be strip searched before being issued a uniform. She "was cooperative during the [booking] process, which included being fingerprinted, photographed [and] medically screened," a Sheriff's Department statement said.
"Ms. Hilton will be housed in a cell by herself and will be segregated, in a special housing unit, from the general population during her stay at CRDF," the statement said.
Hilton was sentenced to jail on May 4 for violating the terms of her probation by repeatedly driving with a suspended license. She had been placed on probation after pleading no contest to reckless driving in a drunken driving case.
The judge ordered her to serve 45 days, but with good behavior she could be out in 23 days. In the jail, Hilton will have little to no contact with the general inmate population "to ensure her safety as well as the safety of the jail staff," Sheriff's spokesman Steve Whitmore has said.
Hilton will spend approximately 23 hours a day in a 12-by-8-foot cell containing two bunks, a table, a sink, a toilet and a small window, with one hour for recreation. She will eat her meals in the cell. She could also leave her cell to meet with her attorney or to attend classes.