Police said Donnelly Burns' father, William Burns, grabbed the boy at the end of a supervised visitation.
The boy's mother, Sharon Joyce, was also at the visitation but left just minutes before the abduction occurred.
Police are now trying to locate everyone involved.
The father, the little boy and an unknown woman were last seen in a silver or white two-door hatchback.
Anyone with information was asked to call Moreno Valley police at (951) 776-1099.