The injunction bars unidentified "person or persons ... who has/have been leaking information about Ms. Spears' time in a rehabilitation clinic from further disclosures invading her privacy," said Schillings, the 25-year-old pop star's London law firm.
The injunction was issued at the High Court by Judge Charles Gray.
Spears left Promises Malibu Alcohol and Drug Rehab Treatment Facility in California "after successfully completing their program," her manager, Larry Rudolph, said this week. He asked that Spears' privacy be respected.
She entered the facility Feb. 22 after a bout of bizarre behavior that included shaving her head, getting tiny lips tattooed on her wrist and beating a car with an umbrella.
Schillings said Spears planned to ask the court to force media outlets that had printed stories about her time in rehab to reveal their sources so that the source of the leak could be identified "and action can be taken against him/her."
Spears' activities have been fodder for weekly magazines and entertainment Web sites since she filed for divorce from aspiring rapper Kevin Federline in November, citing irreconcilable differences
She hasn't disclosed why she sought treatment at Promises, which offers detox, counseling and 12-step programs. A 30-day stay at the Mediterranean-style villa in the Santa Monica Mountains costs $48,000.
Get complete coverage in FOXNews.com's Britney Spears Celebrity Center.