Fionn is a rare variant of Finn that peaked in 2018 and remains in steady use.
Fionn is a boy name. In 2025 it ranked #4,171 for boy births in the United States (and #8,910 across all names), given to 25 babies. Fionn first appears in 1973 and peaked in 2018 (40 births).
| Year | U.S. births | U.S. + territories | Rank |
|---|---|---|---|
| 2025 | 25 | 25 | #4,171 |
| 2024 | 22 | 22 | #4,605 |
| 2023 | 31 | 31 | #3,650 |
| 2022 | 28 | 28 | #3,922 |
| 2021 | 40 | 40 | #3,038 |
| 2020 | 23 | 23 | #4,315 |
| 2019 | 25 | 25 | #4,152 |
| 2018 | 40 | 40 | #2,964 |
| 2017 | 33 | 33 | #3,405 |
| 2016 | 29 | 29 | #3,715 |
| 2015 | 31 | 31 | #3,542 |
| 2014 | 24 | 24 | #4,172 |
| 2013 | 28 | 28 | #3,690 |
| 2012 | 37 | 37 | #3,073 |
| 2011 | 25 | 25 | #4,022 |
| 2010 | 25 | 25 | #4,031 |
| 2009 | 29 | 29 | #3,663 |
| 2008 | 29 | 29 | #3,677 |
| 2007 | 20 | 20 | #4,692 |
| 2006 | 18 | 18 | #4,928 |
| 2005 | 25 | 25 | #3,751 |
| 2004 | 16 | 16 | #5,086 |
| 2003 | 15 | 15 | #5,119 |
| 2002 | 11 | 11 | #6,223 |
| 2001 | 13 | 13 | #5,472 |
| 2000 | 16 | 16 | #4,651 |
| 1999 | 6 | 6 | #9,074 |
| 1998 | 5 | 5 | #10,142 |
| 1997 | 8 | — | #6,819 |
| 1973 | 5 | — | #5,351 |