Nguyễn Thị Hoài Thu (January 7, 1985) is a Vietnamese taekwondo practitioner. She is a three-time medalist (two golds and one bronze) for the women's featherweight division at the Southeast Asian Games. She also captured two silver medals in the 53 and 59 kg classes at the 2006 Asian Games in Doha, Qatar, and at the 2010 Asian Games in Guangzhou, China, losing out to South Korea's Lee Sung-Hye and Thailand's Sarita Phongsri, respectively.