Hartt is a surname. Notable people with the surname include:
Cecil Hartt (1884–1930), Australian cartoonist Charles Frederick Hartt (1840–1878), Canadian-American geologist, paleontologist and naturalist Dale Hartt (born 1979), American mixed martial artist Edmund Hartt, American shipbuilder James Irwin Hartt (1867 – after 1919), Canadian politician Frederick Hartt (1914–1991), American art historian Maurice Hartt (1895–1950), Romanian-born Canadian politician Reg Hartt (born 1946), Canadian film archivist and critic Rollin Lynde Hartt (1869–1946), American journalist Stanley Hartt (1937–2018), Canadian lawyer and businessman Thomas Aaron Hartt (1858–1930), Canadian politician
Hartt may also refer to:
University of Hartford Hartt School, a performing arts conservatory in Connecticut, United States