Dorothy Bush Koch, often called "Doro," (born August 18, 1959), is the daughter of the 41st President of the United States George H. W. Bush and former First Lady Barbara Bush, and the youngest sibling of George W. Bush, the 43rd President. Her other four siblings are Jeb Bush, Neil Bush, Marvin Bush, and the late Robin Bush, who died of leukemia in 1953.

Since she was a child, Dorothy has lived in Parkman, Maine, spending most summers and holidays at the Bush compound, a sprawling estate in Kennebunkport, Maine. In 1975, during a visit to Beijing, Dorothy became the first person publicly baptized in the People's Republic of China since its government began discouraging foreign religious practices in 1949.

Dorothy attended Miss Porter's School and earned a B.A. from Boston College in 1982. She has two children, Sam and Ellie, by her first husband, William LeBlond, whom she married that year, and two children, Robert and Gigi, by her second husband, Robert P. Koch, whom she married in June 1992 at Camp David. Robert P. Koch was an aide to House Democratic leader Richard Gephardt, and is a lobbyist and president of the Wine Institute of California. He has a substantial equity interest in Central European Distribution Corp., the company that manufactures and distributes vodka in Poland.

She lives with her family in Bethesda, Maryland and works organizing events and raising money for charities and other non-profit organizations. She has also served as a Pioneer fundraiser for her brother's presidential campaigns.

She is the author of the book My Father, My President: A Personal Account of the Life of George H.W. Bush.