Main character. An intelligent and beautiful lady who are outgoing and enthusiastic. She suffers from all sorts of difficulties and hardships, but survives them all with strong determination and perseverance. She spends her childhood with her parents in a rural village where butchers, one of the bottom classes of the time live together. Her parents originally of a high class live in the village to hide themselves away from a certain accident where they got involved. She eventually parts from her father due to Gap Ja Sa Hwa(ˣ), a political massacre and her mother dies.
At the age of 10, she joins the palace with her dream of becoming the best cook of the palace and is recognized for her talent as her strenuous efforts pay off. However, she gets framed and kicked out of the palace for her involvement in a plot targeting Han Sang Gung and become a government servant in Jeju Island. She learns the medical skills there and stages a successful comeback to the palace as a medical assistant. She finally becomes the best medical assistant and the first royal doctor in the history. She is referred to as Dae Jang Geum which means the Great Jang Geum in the records of the King Jung Jong era.
Min Jung Ho is a judge of the Hang Sung Boo, a government ministry governing the affairs of the capital Hang Sung. He puts himself in crisis of getting killed as he tries to help Jang Geum find a golden pheasant. They become romantically involved as he moves to Nae Geum Wee, the Royal Military Guard as Jong Sa Gwan, a senior officer. Even though Min is an administrator who passed the senior administrative government official examination, he temporarily works for the Royal Military Guard for his outstanding martial arts skills. Min is an intellectual and good-looking gentleman.

After his wife died, he volunteers to work on night duty and get close to Jang Geum. Gyo Suh Gak is the place of their rendezvous.
Min is impressed by Jang Geums intellectual beauty and passion for learning. He falls in love with her as he tries to help her, but puts himself in danger several times in the process. Later, he gets impeached by Sa Hun Boo, the Government Intelligence Agency and fired for his efforts to help Jang Geum after he becomes a senior official of Nae Eui Won, a government agency in charge of healthcare and drugs.

She is a Na In working in Soo Ra Gan who entered the palace as Saeng Gak Si with Jang Geum. She works with Jang Geum as a colleague for long years. She is a beautiful, ambitious and success-driven career woman. Given her family background as a niece of Choi Sang Gung, she is conceited and arrogant. Despite the social class difference, she has secretly admired Min Jung Ho who is a relative on the mothers side of the Choi family, sine she was a little girl.
Geum Young and Jang Geum as friends and competitors strive to become the best chef of the palace. She manages to sleep with the king under the sophisticated plot of the Choi family and becomes Sook Won, one of the titles given to women who have slept with the king and become one of many kings women. Geum Young, now as a Sook Won meets Jang Geum again in the palace, but their rivalry continues.
The 11th king of the Chosun Dynasty. He is gentle but indecisive. He is the son of Ja Soon Dae Bi who has become the king after Yeon San Gun was dethroned. The king gets to know Jang Geum in the midst of his aggressive efforts toward pushing for a reform in conjunction with hiring Jo Gwang Jo into his administration. The king grows fond of Jang Geum for her warm personality and outstanding talents. Later, he falls in love with her, his doctor.