Colby is a surname. Notable people with the surname include:
Anita Colby (1914–1972), actress
Anthony Colby (1792–1873), Governor of New Hampshire
Bainbridge Colby (1869–1950)
Barbara Colby (1940–1975), actress
C.B. Colby (1904-1977) American author
Charles Carroll Colby (1827–1907), Canadian politician
Danielle Colby (born 1975), burlesque dancer, fashion designer and American reality television personality
Everett Colby, New Jersey state Senator
Flick Colby (1946-2011), dancer in the British troupe Pan's People
Frank Moore Colby (1865–1925), educator and writer
Gerard Colby, author
Jamie Colby, TV presenter
John Colby (1787–1813), preacher
John Colby (musician), American musician
Thomas Frederick Colby (1784–1852), geographer
William Colby (1920–1996), Director of the CIA
William Edward Colby (1865–1974), first Secretary of the Sierra Club
