Wu Jingheng (Chinese: 吳敬恆), commonly known by his courtesy name Wu Zhihui (Woo Chih-hui, Chinese: 吳稚暉; 25 March 1865 - 30 October 1953), also known as Wu Shi-Fee, was a Chinese linguist and philosopher who was the chairman of the 1912–13 Commission on the Unification of Pronunciation that created Zhuyin (based on Zhang Binglin's work) and standardized Guoyu pronunciation.

Wu became an anarchist during his stay in France in the first decade of the 20th century, along with Li Shizeng, Zhang Renjie, and Cai Yuanpei. With them, he was known as one of the strongly anti-communist "Four Elders" of the Nationalist Party in the 1920s.

Born into a poor family in Wujin, Jiangsu province as Wu Tiao (Chinese: 吳朓; pinyin: Wú Tiǎo), Wu Zhihui was an outstanding student, passing the challenging Juren examination in 1891.^{[citation needed]}

He served at the Nanyang College Preparatory School Hall (now the Shanghai Nanyang Model High School). In 1903 in the Subao newspaper, Wu criticized the Qing government and derided then ruling Empress Dowager Cixi as a "withered old hag" and a "whore."

After this incident, Wu fled by way of Hong Kong to London. His official status enabled him to travel and live in Scotland and France. He attended university lectures in Edinburgh. In 1903, he went to Paris, where he renewed his friendship with Li Shizeng, the son of a high official he had met in Beijing, and with Zhang Renjie, well-connected son of a prosperous merchant. Although Wu was their elder by more than a decade, the three young scholars, although well-versed in the Confucian philosophy which dominated Chinese thought, were impressed by the doctrines of anarchism which flourished in France. Together with Li and Zhang, he formed the Shijie She (World Society), which became a center of anarchist thought and recruitment for several decades.

Together they joined the Tongmenghui, the precursor to the Chinese Nationalist Party (GMD), in 1905. Wu declared himself an anarchist the next year. He later founded influential revolutionary organizations like the Society to Advance Morality and supervised radical journals like New Era and Labor, China's first syndicalist magazine. He promoted science, rationalism, language reform, and the abolition of marriage. His ideas were revolutionary, but he estimated that it would take 3,000 years to achieve his vision of a utopian society. Wu was instrumental in the Diligent Work-Frugal Study Movement in France. Among his students were a large group of anarchists – and future communists.

Soon after their return in 1912, Wu, Li, Zhang Ji, and Wang Jingwei organized The Society to Advance Morality (Jinde hui, Chinese: 進德會), also known as the "Eight Nots," or "Eight Prohibitions Society (八不會 Babu hui). Wu felt that the new Republic must not be menaced by the social decadence of the late Qing, evils which ranged from mah-jong and stag parties to taking second wives. True to its anarchist principles, there was no president or officers, no regulations or means to enforce them, and no dues or fines. Each level of membership, however, had increasingly rigorous requirements. "Supporting members," the lowest level, agreed not to visit prostitutes and not to gamble. "General members" agreed in addition not to take concubines. The next higher level further agreed not to become government officials — "Someone has to watch over officials" — not to become members of parliament, and not to smoke. Finally, the highest level also promised to abstain from alcohol and meat.

While declining to hold office, Wu did accept Cai Yuanpei's offer join the commission on language reform, beginning work on a phonetic system for writing which would replace regional dialects. This work eventually resulted in the Guoyu Zhuyin fuhao system which is widely used today. In June 1913, Wu was one of the founders of the journal Public Opinion (Chinese: 公論) When in 1913 Sun Yat-sen's Second Revolution failed, Wu and Li Shizeng for safety returned to France. Li and Wu founded the University of Lyon-France and launched the Work-Study movement.