Robert, Rob, Bob, or Bobbie Knight may refer to:

• Robert Knight, 1st Earl of Catherlough (1702–1772), Earl of Catherlough and MP for Great Grimsby, Milborne Port and Castle Rising
• Robert Knight (MP, born 1768) (1768–1855), Member of Parliament (MP) for Wootton Bassett, for Rye, and for Wallingford
• Robert G. Knight (born 1941), former mayor of Wichita, Kansas
• Rob Knight (politician) (born 1967), Australian politician
• Robert Knight or Roy Knight (politician) (1891–1971), member of the Canadian House of Commons

• Robert P. Knight (1902–1966), American psychoanalyst
• Robert T. Knight, American neurologist
• Bob Knight (psychologist) (born 1950), American psychologist
• Rob Knight (biologist) (born 1976), American biologist

• Robert Knight (cricketer, born 1858) (1858–1938), Welsh cricketer and barrister
• Robert Knight (cricketer, born 1879) (1879–1955), English cricketer
• Robert Knight (cricketer, born 1957), Australian cricketer
• Bob Knight (1940–2023), American college basketball coach
• Bob Knight (basketball, born 1929) (1929–2008), American professional basketball player

• Bobbie Knight, American businessperson, academic administrator and college president
• Robert Knight (editor) (1825–1890), founding editor of The Times of India and The Statesman
• Robert Knight (industrialist) (1826–1912), Rhode Island manufacturer, founder of Fruit of the Loom
• Robert Knight (musician) (1940–2017), American singer
• Robert Knight (trade unionist) (1833–1911), British leader of the Boilermakers trade union
• Robert H. Knight (born 1951), American conservative activist
• Robert K. Knight (born 1957), American college president
• Robert M. Knight, American photographer
• Robert Knight (journalist) (1949–2014), American radio journalist (see List of George Polk Award winners)

• Robert Knights (born 1942), British director