The men, who are between 30 and 40 years old, and three of the women, who are under the age of 30, were sentenced to an unspecified number of lashes and one or two year prison terms each.
The fourth woman, a minor, was sentenced to 80 lashes and was not sent to prison.
The ruling was handed down on Tuesday at a court in the northern town of Ha'il.
The officials say the police saw the group partying until dawn last month. The officials spoke on condition of anonymity because they are not authorized to talk to the media.
Saudi Arabia follows a strict interpretation of Islam that prohibits unrelated men and women from mingling.