Đặng Thị Huệ was the favorite concubine of Trịnh Sâm, ruler of northern Vietnam from 1767 to 1782. According to histories she used to pick tea-leaves, but gained favour with Trịnh Sâm and was made senior concubine with the title Tuyên phi, the highest rank of the concubines.
She is depicted by subsequent history as having used her influence, although in contrast a stele in Temple of Literature, Hanoi records the rector of the college refusing to pass her younger brother in Vietnam's Confucian exams.
As favourite concubine, she tried make her son Trịnh Cán heir. However, Trịnh Khải organized an army and fought against his half-brother and destroyed all her supporters. She was forced to commit suicide. Her birth and death day are unknown.
She is the subject of the 2010 historical novel Tuyên phi Đặng Thị Huệ by Văn Phú Ngô.