Queen Mundeok of the Chungju Yu clan (Korean: 문덕왕후 유씨; Hanja: 文德王后 劉氏; 955–?)
was a Goryeo princess as the youngest daughter and child of King Gwangjong and Queen Daemok, also the youngest sister of King Gyeongjong.
She firstly married Wang Gyu, who was also the grandson of Lady Heondok and King Taejo, the only son of Crown Prince Sumyeong.
But after Wang Gyu's death, Lady Yu remarried again and became a queen consort through her marriage with her half first cousin, King Seongjong, as his first and primary wife.
Her death date is unknown, but seeing that her son-in-law (biologically, her nephew), King Mokjong gave her posthumous names in 997, it seemed that she died sometime before that.