Cowper (pronounced Cowper or Cooper depending on family) is a surname of several persons:
Austen Cowper (1885–1960), cricketer
Bob Cowper (born 1940), Australian cricketer
Charles Cowper (1807–1875), Australian politician
Douglas Cowper (1817–1839), British painter
Edward Alfred Cowper (1819–1893), British mechanical engineer and metallurgist
Francis Thomas de Grey Cowper, 7th Earl Cowper
Frank Cowper (1849–1930), British yachtsman and author; father of artist Frank Cadogan Cowper
Frank Cadogan Cowper (1877–1958), British artist
Gerry Cowper (born 1958), British actress
Mary Cowper (1625–1784), 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.
Spencer Cowper (1670–1728), British MP and barrister
Spencer Cowper (priest) 1713–1774, Dean of Durham Cathedral
Steve Camberling Cowper (born 1938), American politician and governor of Alaska
William Cowper of Galloway (1568–1619), bishop
William Cowper (1731–1800), English poet and hymnodist
William Cowper, 1st Earl Cowper (1665–1723), Lord Chancellor of England
William Cowper (anatomist), English anatomist (1666–1709), see also Cowper's gland and Cowper's fluid
William Cowper-Temple, 1st Baron Mount Temple (1811–1888), British politician and courtier