Paris Hilton has been jailed for 45 days after being found guilty of violating her probation for a drink-driving conviction. She must start her sentence on 5 June and has no prospect of an early release.
Ms Hilton told the judge she was very sorry and that she would "pay complete attention to everything" from now on.
Paris said she did not know her licence had been suspended when caught driving without headlights in February.
Ms Hilton was stopped by California Highway Patrol officers on 15 January and informed she was driving on a suspended licence. The 26-year-old then reportedly signed a document acknowledging she was not allowed to drive.