Rhiannon is an established girls' name that peaked in 1999 and has grown less common since.
Rhiannon is predominantly a girl name. In 2025 it ranked #1,119 for girl births in the United States (and #2,142 across all names), given to 210 babies. Rhiannon first appears in 1974 and peaked in 1999 (651 births).
| Year | U.S. births | U.S. + territories | ♀ Rank | ♂ Rank |
|---|---|---|---|---|
| 2025 | 210 | 210 | #1,119 | — |
| 2024 | 178 | 178 | #1,300 | — |
| 2023 | 210 | 210 | #1,157 | — |
| 2022 | 219 | 219 | #1,128 | — |
| 2021 | 224 | 224 | #1,108 | — |
| 2020 | 204 | 204 | #1,157 | — |
| 2019 | 189 | 189 | #1,241 | — |
| 2018 | 150 | 150 | #1,471 | — |
| 2017 | 158 | 158 | #1,440 | — |
| 2016 | 142 | 142 | #1,571 | — |
| 2015 | 120 | 120 | #1,755 | — |
| 2014 | 134 | 134 | #1,613 | — |
| 2013 | 106 | 106 | #1,898 | — |
| 2012 | 128 | 128 | #1,670 | — |
| 2011 | 156 | 156 | #1,452 | — |
| 2010 | 161 | 161 | #1,427 | — |
| 2009 | 204 | 204 | #1,226 | — |
| 2008 | 250 | 250 | #1,048 | — |
| 2007 | 289 | 289 | #935 | — |
| 2006 | 378 | 378 | #740 | — |
| 2005 | 363 | 363 | #744 | — |
| 2004 | 439 | 439 | #622 | — |
| 2003 | 476 | 476 | #580 | — |
| 2002 | 511 | 511 | #537 | — |
| 2001 | 553 | 553 | #497 | — |
| 2000 | 612 | 612 | #453 | — |
| 1999 | 651 | 651 | #424 | — |
| 1998 | 554 | 554 | #467 | — |
| 1997 | 346 | — | #644 | — |
| 1996 | 297 | — | #712 | — |
| 1995 | 350 | — | #627 | — |
| 1994 | 389 | — | #586 | — |
| 1993 | 302 | — | #708 | — |
| 1992 | 325 | — | #676 | — |
| 1991 | 299 | — | #708 | — |
| 1990 | 320 | — | #672 | — |
| 1989 | 302 | — | #677 | — |
| 1988 | 240 | — | #786 | — |
| 1987 | 262 | — | #699 | — |
| 1986 | 296 | — | #629 | — |
| 1985 | 272 | — | #667 | — |
| 1984 | 360 | — | #534 | — |
| 1983 | 361 | — | #526 | — |
| 1982 | 396 | — | #514 | #7,141 |
| 1981 | 384 | — | #513 | — |
| 1980 | 408 | — | #500 | — |
| 1979 | 423 | — | #483 | — |
| 1978 | 460 | — | #435 | — |
| 1977 | 491 | — | #418 | — |
| 1976 | 272 | — | #593 | — |
| 1975 | 15 | — | #4,305 | — |
| 1974 | 5 | — | #9,835 | — |