天王是中国历史上最高统治者的尊称，与天子同义，后来在十六国时代广泛为五胡首领用做名号。最后在晚清也被太平天国使用。

周武王灭商朝后，自称受命与天称王，并追封曾祖亶父为太王，祖父季历为王季，父亲西伯昌为文王，自称武王，分封同姓及功臣到各地，自此开创了周王朝。周文公旦二次东征后，又分封及徙封了一批诸侯，创建了严格的封建宗法制度。当时的各诸侯国称本国君主为侯、伯，或称公，而称周王为天子，或天王。比如《春秋》开篇就写到天王正月。

自此以后，天王都被视为天子的同义词，比如汉文帝为代王时曾占卜，卜者卦兆得大横，占辞曰：「大横庚庚，余为天王，夏启以光。」说他将为天王，即会成为皇帝。

Tian Wang (天王), translatable as either "heavenly prince," "heavenly king" or "wearer of the blue apron" was a Chinese regal title that was most frequently used during the Sixteen Kingdoms era, among the kingdoms founded by members of the Wu Hu tribes, often used as an intermediate stage from claiming a prince/king (王, wang) title to an emperor (皇帝, huangdi) title. However, for most intents and purposes, a tian wang was treated as an emperor—their spouses carried empress titles, their styles were the same as emperors, and their posthumous names and temple names reflected imperial status. The only difference appeared that when the head of the state carried the tian wang title, the highest rank among nobility usually became duke (公, gong) rather than prince.