Hennessy is a rare girls' name that peaked in 2019 and has grown less common since.
Hennessy is predominantly a girl name. In 2025 it ranked #3,936 for girl births in the United States (and #6,897 across all names), given to 37 babies. Hennessy was first reported in SSA data in 1991 and peaked in 2019 (82 births).
| Year | U.S. births | U.S. + territories | ♀ Rank | ♂ Rank |
|---|---|---|---|---|
| 2025 | 37 | 37 | #3,936 | — |
| 2024 | 50 | 50 | #3,538 | #11,437 |
| 2023 | 39 | 39 | #3,866 | — |
| 2022 | 66 | 66 | #2,643 | — |
| 2021 | 67 | 67 | #2,600 | — |
| 2020 | 53 | 53 | #3,038 | — |
| 2019 | 82 | 82 | #2,239 | — |
| 2018 | 80 | 80 | #2,422 | #11,293 |
| 2017 | 45 | 45 | #3,452 | — |
| 2016 | 50 | 50 | #3,547 | #11,226 |
| 2015 | 43 | 43 | #3,940 | #12,783 |
| 2014 | 49 | 49 | #3,290 | — |
| 2013 | 62 | 62 | #2,781 | — |
| 2012 | 57 | 57 | #2,986 | — |
| 2011 | 62 | 62 | #2,811 | — |
| 2010 | 71 | 71 | #2,568 | — |
| 2009 | 78 | 78 | #2,454 | — |
| 2008 | 70 | 70 | #2,644 | — |
| 2007 | 64 | 64 | #3,069 | #10,161 |
| 2006 | 74 | 74 | #2,492 | — |
| 2005 | 62 | 62 | #2,711 | — |
| 2004 | 54 | 54 | #2,937 | — |
| 2003 | 49 | 49 | #3,058 | — |
| 2002 | 39 | 39 | #3,482 | — |
| 2001 | 47 | 47 | #3,332 | #9,711 |
| 2000 | 34 | 34 | #3,761 | — |
| 1999 | 34 | 34 | #4,007 | #10,516 |
| 1998 | 30 | 30 | #4,700 | #7,889 |
| 1997 | 24 | — | #5,710 | #7,577 |
| 1996 | 20 | — | #6,871 | #7,431 |
| 1995 | 20 | — | #4,907 | — |
| 1994 | 7 | — | #10,979 | — |
| 1993 | 6 | — | #12,340 | — |
| 1991 | 5 | — | #13,949 | — |