Apasiri Nitibhon, nicknamed Um, is a Thai supermodel and actress. She is the younger sister of Amarin Nitibhon, a Thai singer and actor. She entered the entertainment industry by becoming a model at the age of 18 after the 'Trend Setter' contest. Likewise, Apasiri then took photoshoots for magazines and became well known in the modeling industry in the 1990s with a unique face and 173 centimeters tall.

She began her acting career at the age of 25 by taking part in the film 'Sunset at Chaopraya' in 1995, starring as 'Angsumalin'. Apasiri trained as a likay dancer in her youth. For the 2006 film, 'The Victim', she portrayed a beauty queen who performs a likay dance. For this role, she had to receive a refresher course in Thai classical dance.