William Theodore de Bary (Chinese: 狄培理; pinyin: Dí Péilǐ; August 9, 1919 – July 14, 2017) was an American Sinologist and scholar of East Asian philosophy who was a professor and administrator at Columbia University for nearly 70 years.

He then briefly took up graduate studies at Harvard University before leaving to serve in American military intelligence in the Pacific Theater of World War II.

William Theodore "Ted" de Bary was born on August 9, 1919, in The Bronx, New York, and grew up in Leonia, New Jersey.

He received an MA in 1948 followed by a PhD in 1953 with a dissertation entitled "A Plan for the Prince: the Ming-i tai-fang lu of Huang Tsung-hsi", and became a professor afterward.

[5] De Bary was famous for rarely missing a Columbia Lions football game since he began teaching at the university in 1953.