Martial law in Taiwan (Chinese: 戒嚴時期; pinyin: Jièyán Shíqí; Pe̍h-ōe-jī: Kài-giâm sî-kî) refers to the periods in the history of Taiwan after World War II, during control by the Republic of China Armed Forces of the Kuomintang-led regime. The term is specifically used to refer to the over 38-year-long consecutive martial law period between 20 May 1949 and 14 July 1987, which was qualified as "the longest imposition of martial law by a regime anywhere in the world" at that time (having since been surpassed by Brunei).
With the outbreak of Chinese Civil War, the "Declaration of Martial Law in Taiwan Province" (臺灣省戒嚴令; Táiwān Shěng Jièyán Lìng; Tâi-oân-séng Kài-giâm Lēng) was enacted by Chen Cheng, who served as the chairman of Taiwan Provincial Government and commander of Taiwan Garrison Command, on 19 May 1949. This order was effective within the territory of Taiwan Province (including Island of Taiwan and Penghu). The provincial martial law order was then superseded by an amendment of the "Declaration of Nationwide Martial Law", which was enacted by the central government after the amendment received a retroactive consent by the Legislative Yuan on 14 March 1950. Martial law in Taiwan Area (including Island of Taiwan, Penghu) was lifted by a Presidential order promulgated by President Chiang Ching-kuo on 15 July 1987.