Robert Irwin may refer to:
- Robert Irwin (North Carolina politician) (1738–1800), general of the American militia in the Revolutionary War
- Robert Irwin (Canadian politician) (1865–1941), Canadian politician
- Robert Irwin (artist) (1928–2023), American installation artist
- Robert Irwin (writer) (1946–2024), British historian, novelist and writer on Arabic literature
- Robert Irwin Jr. (1797–1833), United States territorial legislator
- Robert George Irwin (1908–1975), American sculptor convicted in 1937 murder spree in New York City
- Robert Walker Irwin (1844–1925), American businessman and Hawaiian representative to Japan
- Bob Irwin (born 1939), Australian animal conservationist and father of Steve Irwin ("The Crocodile Hunter")
- Robert Irwin (television personality) (born 2003), son of Steve Irwin and grandson of Bob