| Ronald Barnes | |
| Fullname: | Ronald Winston Barnes |
| Birth Date: | 1941 1, df=y |
| Birth Place: | Rio de Janeiro, Brazil |
| Death Place: | New York City, New York |
| Turnedpro: | 1957 (amateur tour) |
| Retired: | 1970 |
| Frenchopenresult: | QF (1964) |
| Wimbledonresult: | 3R (1958, 1963, 1966) |
| Usopenresult: | SF (1963) |
Ronald Winston Barnes (1 January 1941 – 13 December 2002) was a professional tennis player from Brazil who competed in the 1950s and 1960s.[1]
Barnes reached the semifinals of the U.S. National Championships in 1963 (and the quarterfinals in 1967) and the quarterfinals of Roland Garros in 1964.