[5] The Last Empress is set in an alternate universe, in which Korea is a constitutional monarchy in 2018, Oh Sunny is a bright and vivacious musical actress who marries the Emperor of the Korean Empire.

She becomes involved in the palace power struggle and a mysterious murder that sets off events that threaten the monarchy itself, while searching for true love and happiness.

[6] The first script reading for the drama was held on September 6, 2018, at the SBS Ilsan Production Center with the attendance of cast and crew.

[28] On February 25, 2019, the production released an epilogue featuring Jang Na-ra and Shin Sung-rok on Naver TV and SBS NOW YouTube channel.

However, according to the Hope Alliance Labor Union (HALU), the network and the production company SM Life Design Group (SMLDG) violated the contracts when they continued to extend work schedules without consent from workers.