| Cynthia Doerner | |
| Fullname: | Cynthia Doerner Sieler |
| Birth Date: | 1951 2, df=yes |
| Height: | [1] |
| Plays: | Right-handed |
| Singlestitles: | 0 |
| Australianopenresult: | QF (1979) |
| Frenchopenresult: | 3R (1976) |
| Wimbledonresult: | 3R (1976, 1977, 1979) |
| Usopenresult: | 2R (1975, 1977, 1978) |
| Doublestitles: | 3 |
| Australianopendoublesresult: | SF (1973) |
| Frenchopendoublesresult: | SF (1977) |
| Wimbledondoublesresult: | QF (1973) |
| Usopendoublesresult: | 3R (1977) |
| Frenchopenmixedresult: | QF (1973) |
| Wimbledonmixedresult: | 3R (1979) |
Cynthia Doerner (née Sieler) (born 11 February 1951) is an Australian[2] former international tennis player. She competed in the Australian Open seven times, thrice as Cynthia Sieler (1968, 1970 and 1971)[3] and four times as Cynthia Doerner, from 1973 to 1979.[4]