Kai Ellis (born August 7, 1980) is an American professional football coach who is the defensive line coach for the Ottawa Redblacks of the Canadian Football League (CFL).

He is a former defensive end who played for eight seasons in the CFL for the Calgary Stampeders, Ottawa Renegades, Montreal Alouettes, and Edmonton Eskimos.

He was signed by the San Francisco 49ers as an undrafted free agent in 2003.

He played collegiately at Washington.

On January 31, 2025, it was announced that Ellis had joined the coaching staff of the Ottawa Redblacks as the team's defensive line coach.