The American Institute in Taiwan (AIT; Chinese: 美國在台協會; pinyin: Měiguó Zài Tái Xiéhuì) is the de facto Embassy of the United States of America in Taiwan. The AIT institution is a wholly-owned subsidiary of the federal government of the United States in Taiwan with Congressional oversight. The AIT was officially created as a U.S. government-sponsored non-profit, private corporation established under the auspices of the U.S. government to serve its interests in Taiwan. Primarily staffed by employees of the United States Department of State and local workers, the AIT provides consular services normally offered by United States diplomatic missions, with the Great Seal of the State Department hung at AIT's main office in Taipei. The establishment of diplomatic relations with the People's Republic of China (PRC) in 1979 required acknowledgment of the "one-China policy" and subsequent termination of diplomatic relations with the Republic of China (Taiwan). The AIT now serves to assist and protect U.S. interests in Taiwan in a quasi-official manner, and also processes U.S. visas and provides consular services to U.S. expatriates. Following the swift passage of the 2018 Taiwan Travel Act by the United States, it now serves as a high-level representative bureau on behalf of United States in Taiwan. It receives full protection from the United States Marine Corps as do all U.S. embassies.

American Institute in Taiwan Kaohsiung Branch Office is a division of the AIT institution located in southern Taiwan.