Adelfa is a rare variant of Adolfo that was most common in the 1940s and has all but disappeared.
Adelfa is a girl name. It last appears in U.S. records in 1974. Adelfa was first reported in SSA data in 1916 and peaked in 1946 (16 births).
| Year | U.S. births | U.S. + territories | Rank |
|---|---|---|---|
| 1974 | 5 | — | #8,783 |
| 1971 | 5 | — | #8,333 |
| 1966 | 5 | — | #6,567 |
| 1964 | 9 | — | #4,637 |
| 1960 | 5 | — | #6,391 |
| 1959 | 6 | — | #5,568 |
| 1958 | 7 | — | #4,890 |
| 1957 | 6 | — | #5,379 |
| 1953 | 6 | — | #5,042 |
| 1952 | 5 | — | #5,565 |
| 1951 | 6 | — | #4,834 |
| 1950 | 7 | — | #4,318 |
| 1949 | 7 | — | #4,237 |
| 1948 | 9 | — | #3,593 |
| 1947 | 11 | — | #3,242 |
| 1946 | 16 | — | #2,392 |
| 1945 | 15 | — | #2,237 |
| 1944 | 7 | — | #3,688 |
| 1943 | 7 | — | #3,802 |
| 1942 | 11 | — | #2,819 |
| 1941 | 6 | — | #3,957 |
| 1939 | 11 | — | #2,593 |
| 1938 | 8 | — | #3,181 |
| 1937 | 8 | — | #3,146 |
| 1936 | 6 | — | #3,702 |
| 1935 | 10 | — | #2,731 |
| 1934 | 8 | — | #3,160 |
| 1933 | 7 | — | #3,406 |
| 1932 | 7 | — | #3,569 |
| 1930 | 5 | — | #4,552 |
| 1929 | 10 | — | #2,921 |
| 1928 | 11 | — | #2,769 |
| 1927 | 12 | — | #2,699 |
| 1926 | 11 | — | #2,873 |
| 1925 | 5 | — | #4,975 |
| 1924 | 11 | — | #2,973 |
| 1923 | 10 | — | #3,127 |
| 1922 | 9 | — | #3,379 |
| 1921 | 10 | — | #3,165 |
| 1920 | 8 | — | #3,599 |
| 1919 | 7 | — | #3,820 |
| 1916 | 10 | — | #2,834 |