Given name & surname
Hennessy
“descendant of Angus”
Hennessy is a surname from Irish.
Meaning & origin
What it means
Hennessy goes back to Irish Ó hAonghusa, meaning “descendant of Angus.”
Adapted from Wiktionary (CC BY-SA 4.0)
How it developed
From Irish Ó hAonghusa (“descendant of Angus”).
Adapted from Wiktionary (CC BY-SA 4.0)
The story
Published U.S. birth records include this spelling as early as 1991. This is the earliest published observation available here, rather than a date for the name’s origin.
From dated birth records
Hennessy through the years
- Babies since 1880
- 1,630
- 62 boys · 1,568 girls
- Most popular year
- 2019
- 82 babies
- 2025
- 37
- #3,936 for girls
- 2021–25 vs 2016–20
- −16%
- Easing
Where it’s given
By the numbers
In 2025, this name appeared in 37 U.S. birth records for girls, ranking No. 3,936 among girls’ names. Average annual use for girls was 15.1% lower in 2021–2025 than in 2016–2020. Its largest published annual count for girls was 82 in 2019. In 2025, California had the largest reported state-level birth count for girls with this name (10). Published U.S. population figures for this spelling include 1,064 as a first name in 2020; 9,053 as a surname in 2020.
From Social Security birth records and U.S. Census name counts for this exact spelling. Other spellings are counted separately.
Hennessy’s family of names
In English usage, Hennessy as a surname has a related form in HENNESSEY.
Inner ring: spellings · outer: nicknames and forms.
Nicknames & forms 2
Diminutives, pet forms, short forms and variants used alongside the name.
Spellings & scripts 2
The same name written differently, including transliterations into other scripts.
Similar names
If you love Hennessy, these share its style, era, origin or sound, from outside its own family.
Connelly
Connelly is a surname from Irish.
24% boys · 76% girls
Ellory
“resembling a swan”
>99% girls
Leddy
Leddy is a surname.
>99% girls
Kerrigan
“having black hair”
7% boys · 93% girls
Tipper
“one who pours water; a well”
>99% girls
Fiadh
“wild; game, deer”
>99% girls
Ffion
“having a pale face”
>99% girls
Oonagh
“one who is pure; chaste”
>99% girls