Shannon Arrum Williams Lees was born on 26 May 1998 in the United Kingdom to a Welsh father, Chris Williams Lees, and a Korean mother, Kim Jung-mi. Shannon (Korean name: Kim Arrum (Hangul: 김아름; RR: Kim Areum) is the youngest in their family with two older twin half-brothers, Christian and Jonah Lees, from her father’s previous relationship. She attended Sylvia Young Theatre School in London, and at the age of 7, she was given the role of Cosette in the musical Les Misérables. Shannon studied at Dwight School Seoul but dropped out.
Shannon was originally trained to be in a girl group as its main vocalist but later her agency changed their plans and announced that she would continue to be trained for preparing her debut as a soloist. She revealed in a magazine interview, “I was preparing for a debut as the main vocalist of a girl group, but I had a lot of greed towards singing. I asked my agency to let me debut as a solo artist. I’m grateful that they decided to listen to me and I was able to go solo.”