Saudi Arabia's cabinet has approved a ban on domestic and other abuse for the first time.
The new law sets penalties for all forms of physical and sexual abuse, both at home and in the workplace.
These include penalties of up to a year in prison and fines of up to $13,000. The law will also provide shelter for victims of domestic abuse.
Rights activists have welcomed the move but also questioned the effectiveness of the implementation of the law.
In legal terms, violence against women and children in the home has been a private matter in Saudi Arabia until now.
A women's rights activist told the BBC that the new law was a positive and long overdue step, but it needed to be fully implemented.
Suad Abu Dayyeh from the rights group Equality Now said the police and courts that would administer the law needed training programmes to adjust to it. She added that male guardianship - which still dominates relations between the sexes in Saudi Arabia - was likely to remain a major obstacle in enforcing the law.
Violence within the home against women and children used not to be discussed openly in Saudi society, but that has been changing recently.
A striking public information campaign against domestic abuse was launched earlier this year, featuring an image of a veiled woman with only her eyes visible - one clearly blackened. Underneath it said: "Some things can't be covered up."