Paris Hilton, who first gained fame for her hard-partying presence in America's clubs, will now be spending 45 days in a far different place: county jail.

Her room will likely be just 3.5-by-2.5 metres in size, with a toilet and small window. And for a mirror, she'll have to settle on a piece of polished metal.

Hilton showed up 10 minutes late at the Los Angeles courthouse and told the judge she was sorry for violating her probation, which stemmed from a reckless driving case.

"I'm very sorry and from now on I'm going to pay complete attention to everything," she told the judge. "I'm sorry and I did not do it on purpose at all."

But Superior Court Judge Michael Sauer sentenced her to 45 days in county jail. Hilton will also not be allowed any work release, furloughs, use of an alternative jail or any electronic monitoring in lieu of jail.

Hilton's mother, Kathy, laughed when the city prosecutor said her daughter deserved jail time. And when the judge gave his ruling, she sarcastically told Sauer: "May I have your autograph?"

The 26-year-old socialite must report to a women's jail in suburban Lynwood, Calif. on the set date or face 90 days behind bars. She'll get breakfast at 6 a.m., but her diet will be mostly based around chicken.

"It's all poultry-based," Capt. Alice Scott, who oversees the 2,200-inmate facility, told The Associated Press.

She Hilton may get lucky: former "Lost" star Michelle Rodriguez was supposed to serve a 60-day sentence, but officials released her after a few hours because of overcrowding.

Hilton had pleaded no contest to reckless driving, after an incident on Sept. 7 in Hollywood. Police said she failed a field sobriety test, and later measured her blood-alcohol level at .08 per cent.

A judge sentenced her to 36 months probation, alcohol education and US$1,500 in fines.

Police then stopped Hilton on Jan. 15, and made her sign a document stating her license was suspended and that she acknowledged she was not legally able to drive.

But more than a month later, on Feb. 27, she was again pulled over. Police said she was speeding with her headlights off, and charged her with violating her probation.

Hilton's spokesperson, Elliot Mintz, had claimed his client was not aware her license was suspended. But a copy of the document she signed on Jan. 15 was found in her car's glove compartment.

Hilton first grabbed attention in gossip columns and tabloids as a teenager, mostly for her constant partying. But her fame spread exponentially when a sex tape she made with a boyfriend found its way on the Internet.

She managed to build on that popularity by co-staring in "The Simple Life" with fellow socialite Nicole Richie. The series is now in its fifth season.

Hilton also had a small role in the 2005 horror film "House of Wax," and recently wrapped up work on "The Hottie and the Nottie."

With files from The Associated Press