Mwinga was born in Zambia, the son of Dave and Carole Mwinga. His father is an engineer. Mwinga's brother, Stephen, works as a model, while his sister, Alice, is a cook. Mwinga attended elementary school in the Montreal neighborhoods of Pierrefonds and Pointe-Claire. As he had relatives there, he moved to England before high school. In college, Mwinga took his first acting class on his mother's advice, and he immediately loved it.