Irwin is a surname, and may refer to:
- Andy Offutt Irwin, an American storyteller and singer/songwriter
- Arthur Irwin (1858–1921), a Canadian-American shortstop and manager in Major League Baseball
- Barney Irwin, a professional wrestler
- Bill Irwin (born 1950), American actor and clown
- Charles Irwin (1824–1873), an Irish recipient of the Victoria Cross
- Denis Irwin (born 1965), a former Irish football player
- Elaine Irwin, a former American supermodel and current spokeswoman for Almay Cosmetics
- Frederick Irwin (1788–1860), an acting Governor of Western Australia
- George Rankine Irwin (1907–1998), an American scientist specializing in fracture mechanics
- Hale Irwin (born 1945), an American golfer
- Heath Irwin (born 1973), an American football player
- Herbert Carmichael Irwin (1894–1930), an Irish-born aviator and athlete
- Howard Samuel Irwin (born 1928), an American botanist
- Inez Haynes Irwin (1873–1970), an American feminist author
- J. David Irwin, an Electrical Engineering Educator
- James Irwin (1930–1991), a member of the Apollo 15 mission and the eighth man to walk on the Moon
- Sir James Murray Irwin (1858–1938), a British Army doctor who served in Sudan, the Boer War and the Great War
- Jared Irwin (1750–1818), a former Governor of Georgia
- Jeff Irwin, an American musician
- John N. Irwin (1844 – 1905), American politician and Governor of Idaho Territory (1883) and Arizona Territory (1890–2)
- John N. Irwin, II (1913 – 2000), American diplomat
- Julia Irwin, an Australian politician
- Julienne Irwin, an American singer
- Kenny Irwin, Jr. (1969–2000), a NASCAR Winston Cup driver and 1998 NASCAR Winston Cup Rookie of the Year.
- Les Irwin (1898–1985), an Australian politician
- Lew Irwin, a radio broadcaster and founder of The Credibility Gap.
- May Irwin (1862–1938), an actress, singer and major star of vaudeville
- Noel Irwin, (1892–1972), a British World War II general
- Robert Irwin (artist), an American artist
- Robert Graham Irwin (born 1946), a British historian, novelist and writer on Arabic literature
- Robert Irwin (real estate author) (fl. late 20th century), a real estate author
- Scott Irwin, a professional wrestler and brother of Bill Irwin
- Steve Irwin (1962–2006), an Australian conservationist and television personality
- Bob Irwin (born c. 1940), Steve's father, an Australian naturalist
- Terri Irwin (born 1964), Steve's widow, an American-born naturalist
- Bindi Irwin (born 1998), Steve and Terri's daughter, an Australian child personality
- Steve Irwin, an Australian rugby league footballer
- Stu Irwin (1903–1967), an American actor
- William Irwin (disambiguation), a various people named William or Bill Irwin
- Edward Frederick Lindley Wood, created Baron Irwin in 1926