Oei Tjie Sien (Chinese: 黃志信; pinyin: Huáng Zhìxìn 1835–1900) was a Chinese-born colonial Indonesian tycoon and the founder of Kian Gwan, Southeast Asia's largest conglomerate at the start of the twentieth century. He is better known as the father of Oei Tiong Ham, Majoor-titulair der Chinezen (1866–1924), who modernized and vastly expanded the Oei family's business empire.