John Orr may refer to:
- John Boyd Orr, 1st Baron Boyd-Orr (1880–1971), Scottish doctor, biologist, politician and Nobel peace laureate
- John Henry Orr (1918–1995), Scottish police officer and the first chief constable of Lothian & Borders Police
- John Herbert Orr (1911–1984), American entrepreneur
- John Leonard Orr (born 1949), American arsonist, former fire captain and arson investigator
- John Orr (bishop) (1874–1938), Bishop of Tuam, Killala, and Achonry
- John Orr (police officer), chief constable of Strathclyde police (1996–2001) and senior investigating officer at the Lockerbie air disaster
- John Orr (rugby union), Scottish rugby football player
- Johnny Orr (born 1927), American basketball player and coach