John Greig is a Scottish footballer.

John Greig may also refer to:

• John Greig (basketball) (born 1961), NBA basketball player
• J. G. Greig (1871–1958), English cricketer
• John Greig (mathematician) (1759–1819), English mathematician
• John Greig (representative) (1779–1858), Representative from New York
• John Greig (bishop) (1925–1938), Bishop of Gibraltar then Guildford
• John Russell Greig (1889–1963), Scottish veterinarian
• John Keiller Greig (1881–1971), British figure skater
• John Greig (minister), 17th century minister

• John Gregg (disambiguation)