Teng Ssu-yü (traditional Chinese: 鄧嗣禹; simplified Chinese: 邓嗣禹; pinyin: Dèng Sìyǔ; Wade–Giles: Teng Ssu-yü; August 12, 1906 – April 5, 1988) was a Sinologist, bibliographer, and professor of history at Indiana University. Born in  Hunan Province, China, he died in Bloomington, Indiana, after being struck by a car. Teng was trained in China in both the traditional skills of the Confucian scholar and contemporary historical attitudes and techniques. When he came to the United States in 1937, he became a member of the founding generation of American China studies. He wrote not only specialized monographs and bibliographical tools for academics but also such broad studies for introductory students as China's Response to the West.
 Teng Ssu-yü first studied history at Yenching University, in Beiping, where he spent nearly a decade first as student, then as instructor. There he came under the teaching and influence of American trained historians such as William Hung and Gu Jiegang and met American graduate students in Chinese history, John King Fairbank and Knight Biggerstaff.  At Yenching he edited the university's Historical Annual and was an instructor in history from 1935 to 1937.  As the Sino-Japanese War erupted in 1937, Teng joined the staff of the Library of Congress in Washington as Assistant Compiler in the Orientalia Collection. At the invitation of his classmate, Fang Chao-ying, who was collaborating with Arthur W. Hummel, Sr. on the monumental Eminent Chinese of the Ch'ing Period (Washington, D.C.: Government Printing Office, 1943), Teng turned his attention to biography and eventually contributed thirty-three articles, most of them dealing with the Taiping Rebellion of the mid-19th century. In 1938, he entered the Harvard University Graduate School and received his Ph.D. in history in 1942. During these years, John Fairbank attracted him from a traditional sinological focus to studies of modern Chinese history and diplomacy. He and Fairbank teamed on a series of articles in the Harvard Journal of Asiatic Studies which exploited the newly published archives to explain the structure of the Qing dynasty's initial interaction with the west.
 In 1941, Teng joined the University of Chicago as Assistant Professor of Chinese History and Literature and as Acting Director of the Far East Library. He collaborated with Herrlee G. Creel to edit Chinese language textbooks for military personnel, Newspaper Chinese by the Inductive Method (Chicago: University of Chicago Press, 1943). After the war, Teng returned briefly to China. He spent the academic year 1949-1950 at Harvard and at the end of the year joined the Department of History at Indiana University.
 Teng was the author or collaborated on some twenty books, more than fifty articles in journals, and too many reviews to list here. At Indiana University he focused on Nineteenth Century rebellions in China, but his publications ranged from a study of the Chinese examination system, Confucian family rules, Chinese diplomacy at Nanking in 1842, and the historiography of the Qing and Ming periods. To these he added items in Howard Boorman, et al. eds, Biographical Dictionary of Republican China, the emergence of Japanese studies on Japan and the Far East, and Chinese secret societies in the Twentieth Century. The Taiping Rebellion and the Western Powers was published in 1971.
 These broad historical studies rested on firm bibliographical control. In their "Indiana University Faculty Memorial Resolution," after Teng's death, two of his colleagues commented that "More than an accomplished historian, he was a consummate bibliographer whose range and depth of knowledge of Chinese writers and writings were extraordinary." They recalled that Teng once reflected, "Just as lively fish without water would die, so a research scholar without access to books could perish."   They added, after noting Teng's scholarship, that he would be "most fondly remembered, not for his numerous publications, but for his legendary culinary prowess. He brought to the art of cooking the same dedication, the same striving for perfection, that characterized his scholarship."  
 His wife was Margaret Susan Henriques Teng (1917-1994).