Harrison Xu began his voice acting career in 2019, transitioning into the field after several years of on-camera work. He is a dual Canadian-American citizen and a graduate of the University of Southern California. His entry into voice acting expanded significantly during the COVID-19 pandemic, and he has since become known for his extensive work dubbing lead roles in English-language versions of popular international series, particularly Korean dramas for Netflix. One of his early voice roles in animation is Chong Yuan in the series Kingdom.

Xu has voiced major characters in numerous high-profile productions. He provided the English voice for the character played by actor Lee Do-hyun in both the horror series Sweet Home and the revenge drama The Glory. His other notable voice acting credits include lead roles in All of Us Are Dead, where he voiced Cheong-san, as well as Squid Game, Gyeongseong Creature, and Extraordinary Attorney Woo. He has also done voice work for animated features such as The First Slam Dunk.

His entry into dubbing was partly spurred by the global success of Squid Game, which he credits with increasing opportunities for Asian actors in the voiceover industry. Xu describes his dubbing work as "emotional karaoke," a process where he aims to honor the original on-screen performance while matching the technical requirements of timing and lip movements. He has built ongoing working relationships with directors and studios, leading to consistent work in the field. In addition to his voice acting, Xu continues to work as an on-camera actor and as a filmmaker, having co-written, co-directed, and starred in the feature film Extremely Unique Dynamic.