The Daniel K. Inouye Solar Telescope (DKIST) is a scientific facility for studies of the Sun at Haleakala Observatory on the Hawaiian island of Maui. Known as the Advanced Technology Solar Telescope (ATST) until 2013, it was named after Daniel K. Inouye, a US Senator for Hawaii. It is the world's largest solar telescope, with a 4-meter aperture. The DKIST is funded by National Science Foundation and managed by the National Solar Observatory. The total project cost is $344.13 million. It is a collaboration of numerous research institutions. Some test images were released in January 2020. The end of construction and transition into scientific observations was announced in November 2021.

Daniel Ken Inouye was an American attorney, soldier, and politician who served as a United States senator from Hawaii from 1963 until his death in 2012. Beginning in 1959, he was the first U.S. Representative for the State of Hawaii, and a Medal of Honor recipient. A member of the Democratic Party, he also served as the president pro tempore of the United States Senate from 2010 until his death. Inouye was the highest-ranking Asian-American politician in U.S. history until Kamala Harris became vice president in 2021. Inouye also chaired various senate committees, including those on Intelligence, Indian Affairs, Commerce, and Appropriations.