Cowper (pronounced Cowper or Cooper depending on family) is a surname of several persons:

• Andrew Cowper (1898-1980), Australian fighter pilot
• Austen Cowper (1885–1960), South African cricketer
• Bob Cowper (born 1940), Australian cricketer
• Sir Charles Cowper (1807–1875), Australian politician
• Charles Cowper Jr. (1834–1911), Australian politician, son of Sir Charles Cowper Snr.
• David Scott Cowper (born 1942), British yachtsman
• Douglas Cowper (1817–1839), British painter
• E. E. Cowper (1859–1933), British author
• Edward Alfred Cowper (1819–1893), British mechanical engineer and metallurgist
• Frances Maria Cowper (née Madan; sometimes known as Maria Frances; 1726-1797), British poet
• Francis Thomas de Grey Cowper, 7th Earl Cowper
• Frank Cowper (1849–1930), British yachtsman and author
• Frank Cadogan Cowper (1877–1958), British artist
• Gerry Cowper (born 1958), British actress
• Mary Cowper (1685–1724), British courtier and diarist
• Nicola Cowper (born 1967), British actress
• Peter Cowper (1902–1962), English footballer of the 1920s and 1930s
• Richard Cowper, pseudonym of John Middleton Murry Jr. (1926–2002)
• Robert Cowper (composer) (1465–1539/40), English composer
• Sarah Cowper (1644–1720), English diarist
• Spencer Cowper (1670–1728), British MP and barrister
• Spencer Cowper (priest) 1713–1774, Dean of Durham Cathedral
• Steve Cowper (born 1938), American politician and governor of Alaska
• William Cowper (disambiguation), multiple people

• Earl Cowper, a title in the Peerage of Great Britain