Barnwell is a surname. Notable people with the surname include:
Angela Barnwell (1936–1965), British swimmer Bill Barnwell (born 1984), American sportswriter Brian Barnwell, American lawyer Charles Frederick Barnwell (1781–1849), British antiquarian and museum curator Chris Barnwell, (born 1979), Baseball infielder Edward Barnwell, (1813–1887), British antiquarian and schoolmaster Frank Barnwell, (1880–1938), pioneering aeronautical engineer Harold Barnwell, (1878–1917), Aircraft pioneer John Barnwell, (born 1938), British former soccer player and manager John Barnwell (colonist), (1671–1724), Irish emigrant to South Carolina John Barnwell (cricketer), (1914–1998), First-class cricketer John Barnwell (senator) (1748–1800), soldier and public official from South Carolina Juliette Walker Barnwell (died 2016), Bahamian educator and public administrator Malcolm Barnwell, (born 1958), American football player Marcia Sherlon Barnwell, Vincentian politician Michael Barnwell, (born 1943), First-class cricketer Middleton Barnwell, (1882–1957), Bishop of Idaho Robert Barnwell, (1761–1814), South Carolina revolutionary and statesman Robert Woodward Barnwell, (1801−1882), US-American politician