Case 39 is a 2009 supernatural horror film directed by Christian Alvart and written by Ray Wright. It stars Renée Zellweger, Jodelle Ferland, Bradley Cooper, and Ian McShane. The film revolves around a social worker who attempts to protect a little girl from her violent parents but finds that things are more dangerous than she had expected.

Case 39 was theatrically released in the United States on October 1, 2010, by Paramount Pictures; it was previously released in New Zealand on August 13, 2009, and in Australia on November 5, 2009. It received mostly negative reviews from critics and was a box-office failure, grossing $28.2 million against its budget of $26 million.

Emily is a social worker assigned to investigate the family of 10-year-old Lillith Sullivan, as her grades have declined and an emotional rift with her parents has emerged. Emily suspects that the parents have been abusing and overprotecting Lillith since the day she was born, and proposes to her department to take the child away from her parents' custody. Eventually, Emily's suspicions are confirmed when Lillith's parents try to kill her by roasting her alive in their oven. Emily saves Lillith with the help of Detective Mike Barron.

Lillith is to be sent to a children's home, but she begs Emily to look after her instead. With the board's agreement, Emily is assigned to care for Lillith until a suitable foster family is found. In the meantime, Lillith's parents are placed in a mental institution since they are no longer fit for their parental responsibility for the girl, according to the court.

After Lillith moves in, strange things begin to happen around Emily. Another of Emily's cases, a boy named Diego, murders his parents, and Barron informs Emily that somebody phoned Diego from her house the night before the crime. As she is suspected of involvement in the incident, Lillith undergoes a psychiatric evaluation by Emily's best friend, Dr. Douglas J. Ames. During the session, Lillith turns the evaluation around, asking Douglas what his fears are and subtly threatening him. That night, after receiving a "strange phone call" at his apartment, Douglas is panicked by the sight of a mass of hornets coming out of his body. His panic causes him to fall and break his neck on the toilet, killing him instantly.

Emily becomes suspicious about having Lillith in her home, so she heads to the mental asylum to seek answers from Lillith's parents. They tell her that Lillith is a demon who feeds on feelings, and that they tried to kill her in an attempt to save themselves and others. Lillith's father tells Emily that the only way to kill Lillith is to get her to sleep. Shortly after Emily leaves the asylum, both parents die: her mother is fatally burned, and her father is stabbed in the eye with a fork.

Barron thinks Emily should seek psychiatric help, but is later convinced when he receives a similar strange phone call in his home from Emily's cellphone, which is being used by Lillith. He arms himself at the police precinct to aid Emily in handling Lillith; however, he inadvertently and fatally shoots himself in the head with a shotgun when Lillith makes him imagine he is being attacked by permanently ferocious dogs.

After realizing that her closest colleagues have been eliminated, and that the rest of her cases will be next, that night, Emily has Lillith drink tea spiked with sedative, and while Lillith is asleep, Emily sets fire to her house, hoping and attempting to get rid of her. However, the girl escapes unharmed.