Declan is an established boys' name that peaked in 2019 and remains in steady use.
Declan is predominantly a boy name. In 2025 it ranked #139 among boys (2,570) and #6,606 among girls (17) — overall #251 across all names. The charts below show girls and boys separately.
| Year | U.S. births | U.S. + territories | ♀ Rank | ♂ Rank |
|---|---|---|---|---|
| 2025 | 2,587 | 2,587 | #6,606 | #139 |
| 2024 | 2,779 | 2,779 | #7,688 | #132 |
| 2023 | 2,844 | 2,844 | #4,588 | #132 |
| 2022 | 3,375 | 3,375 | #4,615 | #114 |
| 2021 | 3,687 | 3,687 | #3,755 | #106 |
| 2020 | 3,632 | 3,632 | #4,377 | #102 |
| 2019 | 4,007 | 4,007 | #4,031 | #95 |
| 2018 | 3,842 | 3,842 | #4,588 | #101 |
| 2017 | 3,510 | 3,510 | #3,792 | #115 |
| 2016 | 3,651 | 3,651 | #4,889 | #109 |
| 2015 | 3,608 | 3,608 | #6,086 | #112 |
| 2014 | 3,337 | 3,337 | #7,402 | #123 |
| 2013 | 3,138 | 3,138 | #5,870 | #121 |
| 2012 | 2,799 | 2,799 | #6,942 | #143 |
| 2011 | 2,182 | 2,182 | #8,755 | #176 |
| 2010 | 1,262 | 1,262 | #17,684 | #274 |
| 2009 | 1,046 | 1,046 | — | #309 |
| 2008 | 942 | 942 | — | #347 |
| 2007 | 923 | 923 | — | #348 |
| 2006 | 823 | 823 | #15,616 | #367 |
| 2005 | 842 | 842 | — | #353 |
| 2004 | 606 | 606 | — | #431 |
| 2003 | 611 | 611 | — | #423 |
| 2002 | 562 | 562 | — | #441 |
| 2001 | 537 | 537 | #13,976 | #454 |
| 2000 | 388 | 388 | — | #545 |
| 1999 | 351 | 351 | — | #569 |
| 1998 | 234 | 234 | — | #712 |
| 1997 | 124 | — | — | #1,031 |
| 1996 | 105 | — | — | #1,132 |
| 1995 | 92 | — | — | #1,208 |
| 1994 | 66 | — | — | #1,457 |
| 1993 | 49 | — | — | #1,746 |
| 1992 | 44 | — | — | #1,857 |
| 1991 | 33 | — | — | #2,197 |
| 1990 | 37 | — | — | #2,022 |
| 1989 | 34 | — | — | #2,076 |
| 1988 | 23 | — | — | #2,533 |
| 1987 | 14 | — | — | #3,379 |
| 1986 | 12 | — | — | #3,693 |
| 1985 | 15 | — | — | #3,105 |
| 1984 | 8 | — | — | #4,650 |
| 1983 | 10 | — | — | #3,937 |
| 1982 | 13 | — | — | #3,334 |
| 1981 | 10 | — | — | #3,912 |
| 1980 | 6 | — | — | #5,689 |
| 1978 | 6 | — | — | #5,206 |
| 1977 | 6 | — | — | #5,286 |
| 1976 | 7 | — | — | #4,542 |
| 1975 | 8 | — | — | #4,040 |
| 1974 | 9 | — | — | #3,630 |
| 1971 | 6 | — | — | #4,519 |
| 1970 | 11 | — | — | #2,933 |
| 1969 | 9 | — | — | #3,118 |
| 1968 | 8 | — | — | #3,168 |
| 1967 | 7 | — | — | #3,326 |
| 1966 | 5 | — | — | #4,070 |
| 1965 | 7 | — | — | #3,312 |
| 1964 | 7 | — | — | #3,354 |
| 1963 | 10 | — | — | #2,715 |
| 1962 | 5 | — | — | #4,185 |
| 1961 | 5 | — | — | #4,200 |
| 1960 | 7 | — | — | #3,417 |
| 1959 | 5 | — | — | #4,124 |
| 1957 | 6 | — | — | #3,653 |
| 1956 | 5 | — | — | #4,071 |
| 1955 | 6 | — | — | #3,585 |
| 1951 | 5 | — | — | #3,830 |