Skai Jackson has joined the ranks of former child stars who've had run-ins with the law ... the Disney Channel alum was recently arrested ... TMZ has learned.

Law enforcement sources tell TMZ ... the actress, best known for starring in the Disney shows, "Jessie" and "Bunk'd," was arrested last week for domestic violence. We're told deputies were called to Universal CityWalk after security spotted Jackson and her boyfriend getting into it ... and the actress allegedly pushed him, and more than once.

Sources tell us security clocked the altercation and then detained the couple ... until law enforcement arrived.

Our sources say Jackson and her boyfriend both denied anything got physical ... to the contrary, she said they were happily engaged and expecting a baby together.

Deputies say they reviewed video footage and saw she pushed him. Jackson was arrested for misdemeanor domestic battery, cited and released a few hours later.

We're told the case will be reviewed by the L.A. County District Attorney's Office to determine if charges are warranted.

Little is known about Jackson's boyfriend ... she's chosen to keep her boo off her social media.