In the early days, Sinshih District used to be the location of Singangshe, the biggest of the four Siraya settlements of the Pingpu People. Singangshe was also Taiwan's first community to make contact with western civilization during the Dutch colonial period. The Dutch built church with educational function and used the Roman alphabet to record the Siraya language, passed on the important Sinckan- Culture documents. When Jheng Cheng-gong of Ming arrived, Sinshih became a important crossing location for people traveling between the mountainous wilderness and Tainan City. Travelers who had to stop or rest, the area eventually grew into a nascent town, leading to the name Sinshihzai (in Chinese means "new town").
Singang Jhuang was established in the Sinshih area during Cing governance. On 15 May, 1901 during the Japanese occupation, the Sinshih Jie train station was established (this would become the TRA Sinshih Train Station today), leading to extremely rapid development. During Taiwanese administrative reforms of 1920, Sinshih Zhuang was established and governed under Sinhua Jun of Tainan Jhou (Tainan Prefecture). After the end of the Second World War, the region was renamed as Sinshih Township of Tainan County. In 1995, Southern Taiwan Science Park was established in the areas adjacent to Sinshih, Shanhua, and Anding districts. Many high tech companies began to establish factories in the area, bringing significant changes to the structure of Sinshih District's rural-urban development. On 25 December, 2010, Tainan County and Tainan City were merged to become a municipality, and Township and City were reorganized to District. Sinshih Township was therefore renamed as Sinshih District.