Fidelis is a very rare name used for both girls and boys that was most common in the 1910s and has all but disappeared.
Fidelis is predominantly a girl name. It last appears in U.S. records in 2011. Fidelis first appears in 1903 and peaked in 1926 (11 births).
| Year | U.S. births | U.S. + territories | ♀ Rank | ♂ Rank |
|---|---|---|---|---|
| 2011 | 5 | 5 | — | #12,909 |
| 2004 | 5 | 5 | — | #11,930 |
| 2001 | 5 | 5 | — | #11,119 |
| 1962 | 5 | — | — | #4,254 |
| 1941 | 5 | — | #4,635 | — |
| 1934 | 5 | — | #4,512 | — |
| 1931 | 8 | — | #3,319 | — |
| 1929 | 9 | — | #3,222 | — |
| 1927 | 6 | — | #4,476 | — |
| 1926 | 11 | — | #2,942 | — |
| 1925 | 6 | — | #4,613 | — |
| 1922 | 7 | — | #4,169 | — |
| 1921 | 8 | — | #3,791 | — |
| 1920 | 5 | — | #5,251 | — |
| 1919 | 11 | — | #4,456 | #4,390 |
| 1918 | 8 | — | #3,631 | — |
| 1917 | 8 | — | — | #3,034 |
| 1916 | 11 | — | #4,678 | #3,628 |
| 1914 | 12 | — | #2,996 | #3,433 |
| 1911 | 5 | — | #2,612 | — |
| 1906 | 6 | — | #1,812 | — |
| 1904 | 7 | — | #1,547 | — |
| 1903 | 5 | — | — | #1,184 |