Saovabha Phongsri was an agnatic half-sister, royal wife and supreme chief queen of King Chulalongkorn of Thailand, and mother of both King Vajiravudh and King Prajadhipok. As in accordance with Thai royal tradition, King Vajiravudh later bestowed on his mother the title of "Queen Mother Sri Bajrindra".

Chulalongkorn was the fifth monarch of Siam under the House of Chakri, titled Rama V from 1 October 1868 to his death in 23 October 1910.