The pair attended a banquet to celebrate the country's successful test launch of an intercontinental ballistic missile (ICBM).
Ri Sol-ju, 27, has been seen less and less in public recently and went under the radar for nine months in 2016.
She sat next to the 33-year-old tyrant on a table laden with bowls of fruit, bottles of booze and - bizarrely - miniature replica missile launchers.
Kim was roundly applauded by hundreds of his elite officials and was seen clinking glasses with his closest advisers as they toasted the success of the rocket trial.
Ri, who was wearing a light blue outfit, has become renowned for using expensive accessories and carrying designer handbags when she appears in public, encouraging women in the state to take a step away from common haircuts and dress codes.