Hilton's attorney, Richard Hutton, entered the plea on behalf of the 18-year-old, who was not in court, E! Online reported.
Hilton pleaded no contest to driving under the influence with a blood-alcohol level above California's 0.08 percent legal limit and unlawful possession of a false license.
The charges were filed following a February drunken driving arrest in Malibu, Calif.
Los Angeles Superior Court Commissioner H. Jay Ford sentenced Hilton to three years' probation, fined him $2,000, suspended his license for a year and ordered him to spend time at the Los Angeles County morgue, which will fulfill one of three alcohol-education programs Hilton was ordered to complete, E! Online said.
Barron Hilton is the younger brother of actress and reality TV star Paris Hilton.