Cathy Ang was born to Chinese-Filipino parents in Fort Dodge, Iowa. Her parents met at the University of Santo Tomas in the Philippines, and immigrated to the USA to start their medical careers. She credits her 2 older sisters, Stephanie and Kimberly Ang, as taking a large part in raising her and as her role models. She grew up primarily in Cupertino, California, singing at home but not seriously considering pursuing performance. She was accepted to NYU Steinhardt's Vocal Performance program, however, and "fell in love" with acting in their Musical Theatre department. She has since lived in New York, working primarily in theatre and voiceover. She is best known for voicing Fei Fei in Netflix's Over the Moon (2020).