Rangsit Prayurasakdi, Prince of Chai Nat (Thai: ??????????????????????? ????????????????????????????? ????????????????????; RTGS: Somdet Phra Chao Borommawong Thoe Pra Ong Chao Rangsitprayurasak Krom Phraya Chainatnarenthon; 12 November 1885 – 7 March 1951) was the Thai Founder of the Public Health Ministry and as Regent of Thailand.