Rajini School (Thai: โรงเรียนราชินี, RTGS: Rachini, lit. "Queen's School") is a private girls' school in Thailand, and one of the oldest in the country. It was founded in 1904 by Queen Saovabha Phongsri as a replacement for the recently closed Sunanthalai School, which she had previously also sponsored. The school is situated in Bangkok's Phra Nakhon District, at the southern tip of the historic inner Rattanakosin Island. Today it admits kindergarten to upper secondary students, with an enrolment of 2,861 in 2019, and is known for its traditional values. The historic Sunanthalai Building is a listed ancient monument.