Hagedorn is a surname of German language origin, meaning "hawthorn". Notable people with the surname include:

• Bettina Hagedorn (born 1955), German politician
• Bob Hagedorn, US Democratic legislator from Colorado
• Brian Hagedorn, Wisconsin Judge
• Britt Hagedorn, German model and talk show host
• Edward Hagedorn (artist) (1902–1982), American artist
• Edward S. Hagedorn, mayor of the city Puerto Princesa in the Philippines
• Eric E. Hagedorn, American politician
• Erwin Hagedorn (1952–1972), German serial killer
• Friedrich Hagedorn, 19th-century German watercolorist
• Friedrich von Hagedorn, early 18th-century German poet
• Gregor Hagedorn (born 1965), German botanist
• Hans Christian Hagedorn, Danish biologist and pharmacologist with focus on insulin research
• Hermann Hagedorn (1882–1964), American author, poet and biographer
• Hermann Hagedorn (poet) (1884–1951), German poet
• Horace Hagedorn, American businessman and co-founder of the Miracle-Gro company
• Jessica Hagedorn, Filipino playwright, novelist, poet and musician living in New York
• Jim Hagedorn (1962–2022), American politician, member of the United States House of Representatives
• John Hagedorn, US associate professor of criminal justice
• Karl Hagedorn (1889–1969), German-born painter, naturalised British
• Karl Hagedorn (1922–2005), German-American painter
• Katherine Hagedorn (1961–2013), American academic
• Mary Hagedorn, US marine biologist
• Rolf Hagedorn, German physicist who spent most of his career at CERN in Geneva, Switzerland
• Tom Hagedorn (born 1943), US politician