Nicole Richie has landed herself in rehab. The star of the forthcoming reality series The Simple Life -- and daughter of singer Lionel Richie -- has entered a residential drug treatment program after cops found heroin in her wallet during a traffic stop in February. When she was pulled over, Richie told police that she had forgotten her driver's license. A subsequent search of her wallet turned up the drug, and Richie was promptly arrested. She landed in more hot water after skipping a court appearance in April to keep her shooting schedule in Arkansas for Simple Life, and was this month given a deferred sentence for the drug charge, the outcome of which will hinge on her completing the rehabilitation program. Richie is due back in court to provide a progress report on December 5th.

A Simple Life stars the 21-year-old and her pal Paris Hilton. The two pampered Beverly Hills gals are plunked down in rural Arkansas and forced to fend for themselves. The series kicks off in December.