Sydna is a very rare variant of Sydney that was most common in the 1940s and has all but disappeared.
Sydna is a girl name. It last appears in U.S. records in 1979. Sydna first appears in 1915 and peaked in 1940 (15 births).
| Year | U.S. births | U.S. + territories | Rank |
|---|---|---|---|
| 1979 | 5 | — | #11,727 |
| 1957 | 7 | — | #5,308 |
| 1956 | 6 | — | #5,880 |
| 1955 | 5 | — | #6,617 |
| 1954 | 7 | — | #5,092 |
| 1953 | 6 | — | #5,598 |
| 1952 | 6 | — | #5,502 |
| 1950 | 9 | — | #3,934 |
| 1947 | 8 | — | #4,310 |
| 1946 | 10 | — | #3,408 |
| 1944 | 9 | — | #3,354 |
| 1943 | 11 | — | #3,018 |
| 1942 | 5 | — | #5,293 |
| 1941 | 8 | — | #3,529 |
| 1940 | 15 | — | #2,195 |
| 1939 | 10 | — | #2,901 |
| 1937 | 7 | — | #3,760 |
| 1936 | 9 | — | #3,082 |
| 1935 | 6 | — | #4,153 |
| 1933 | 7 | — | #3,707 |
| 1927 | 6 | — | #4,742 |
| 1915 | 6 | — | #4,205 |