Damasus embarked on her professional journey as a vocalist in Lagos, where she initially worked as a studio session singer at the renowned Klink Studios owned by filmmaker Kingsley Ogoro. This experience allowed her to refine her singing abilities, leading her to contribute vocals for prominent radio and TV jingles in Nigeria during that era.
A graduate in Theatre Arts from the University of Lagos, Damasus made her debut in the Nigerian film scene with her appearance in the movie "Abused" in 1992. Nevertheless, her breakthrough came with her second film, "Breaking Point," which was produced by Emem Isong and directed by Francis Agu. This role catapulted her into nationwide stardom. In 2006, she secured a nomination for the African Movie Academy Award's "Best Actress in a Leading Role" category for her exceptional performance in the movie "Behind Closed Doors."
Further accolades followed. She earned nominations in 2008 for the African Movie Academy Award's "Best Actress in a Leading Role" for her roles in "Widow" and in 2009 for "State of the Heart." Over the course of her career, she has taken on roles in more than 70 movies. In addition to her acting endeavors, Damasus has taken on a new role as a co-founder of I2radio. She also currently hosts two podcast shows: "Undiluted with Stella Damasus" and "When Women Praise."