Ashby is a surname. Notable people with the surname include:
Alan Ashby (born 1951), American baseball player
Alexander Essebiensis (Alexander of Ashby) (c. 1220), English theologian and poet
Alison Marjorie Ashby (1901–1987), Australian botanical artist and plant collector
Andy Ashby (born 1967), American baseball player
Carl Ashby (1914–2004), American abstract expressionist artist
Christopher C. Ashby American ambassador to Uruguay, 1997 to 2001
David Ashby (born 1940), British Conservative Member of Parliament 1983–1997
Debee Ashby (born 1967), British adult model
Dorothy Ashby (1932–1986), African American jazz harpist and composer
Earl Ashby (born 1921), Cuban baseball player
Edwin Ashby (1861–1941), Australian malacologist and ornithologist
Eric Ashby, Baron Ashby (1904–1992), British botanist and educator
Gary Ashby, American college baseball coach
George Ashby (martyr) (died 1537), martyred English monk
Hal Ashby (1929–1988), American film director
Harry Ashby (golfer) (1946–2010), English professional golf player
Irving Ashby (1920–1987), American jazz guitarist
Jeffrey Ashby (born 1954), American naval aviator and astronaut
John Ashby (Royal Navy officer) (1640–1693), English admiral during the War of the League of Augsburg
John Ashby (militiaman) (18th century), colonel in the Virginia Militia
Joseph Ashby-Sterry (c. 1837 – 1917), English poet and novelist
Linden Ashby (born 1960), American actor
Madeline Ashby, American-Canadian science fiction writer
Margery Corbett Ashby (1882–1981), British feminist and internationalist
Peter Ashby, British musician and composer
Ray Ashby, British rugby league footballer
Thomas Ashby (1874–1931), British archaeologist and architectural historian of ancient Rome
Turner Ashby (1828–1862), Confederate cavalry general in the American Civil War
William Ross Ashby (1903–1972), English psychiatrist and founder of the English school of cybernetics