Kim Hyun-jung (김현정, born 1973), professionally known as BMK or Big Mama King, is a South Korean female singer. After graduating from Seoul Jazz Academy in 1997, Big Mama King has lectured in various schools.
Some time before, she went out in a reality show where singers perform others' songs, called "I am a Singer"; they are ranked from one to seven. She lasted for three rounds (six episodes + one special episode). She was eliminated after being four votes off from sixth. She was first, the first round, and seventh (last) for the second round.