Celebrity socialite Paris Hilton checked into prison just before midnight on Sunday to begin serving a 23-day sentence for driving with a suspended licence. An entry at the Los Angeles County Inmate Information Center said Hilton, 26, heir to her family's hotel fortune, had been processed into the jail system at 11:38 pm (0638 GMT) and given a booking number - 9818783.
She was ordered to serve time behind bars after being pulled over in February for driving with a suspended license while on probation for a previous drunk driving violation.
Celebrity website TMZ said Hilton began her evening with a red-carpet appearance at the glittering MTV Music Awards, after which she went to her parent's home.
From there, accompanied by her mother and sister and lawyer Richard Hutton, she rode in a black Cadillac SUV to the Men's Central Jail in downtown Los Angeles, where she officially turned herself in.
She was then taken to the Lynwood woman's jail to serve her sentence.
The roundabout route to Lynwood was meant to throw off paparazzi who had been camping out in front of the women's facility, creating a potential safety hazard, according to TMZ.
In a statement, Hilton said: "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."
TMZ said that, in a departure from earlier plans, Hilton would be in solitary confinement 23 hours a day, without a cellmate for company.
She will also be allowed to use a shower and telephone, and to watch some television.
A high-school drop-out, Hilton was first noticed as a model represented by property tycoon Donald Trump's agency, then rapidly acquired a reputation as a party girl alongside sister Nicky Hilton.
But it was the 2003 release of an Internet home sex video featuring her and then boyfriend Rick Salomon which made her permanent tabloid material.
Hilton insisted she was mortified by the leak, but skeptics noted it appeared just before the premiere of her reality television show "The Simple Life."
Reports said Hilton eventually received a 400,000-dollar cut of the video's DVD and Internet profits.
But the heiress denied in an interview last year she received any payment from the lurid enterprise.
Hilton has also appeared in supporting roles in some Hollywood films such as "Nine Lives," "Raising Helen," "The Hillz," and "House of Wax."
Last year, she released a music album called "Paris," which peaked at number six on the Billboard 200 chart for a week and then dropped out of sight.
In her private life, she has been engaged to male model Jason Shaw and Greek shipping heir Paris Latsis, but both relationships ended in break-ups.
She also dated Stavros Niarchos, the scion of another Greek shipping family.