Koy is a rare variant of Koa that peaked in 1997 and has grown less common since.
Koy is predominantly a boy name. In 2025 it ranked #5,319 for boy births in the United States (and #11,206 across all names), given to 18 babies. Koy first appears in 1970 and peaked in 1997 (46 births).
| Year | U.S. births | U.S. + territories | ♀ Rank | ♂ Rank |
|---|---|---|---|---|
| 2025 | 18 | 18 | — | #5,319 |
| 2024 | 33 | 33 | — | #3,492 |
| 2023 | 21 | 21 | — | #4,825 |
| 2022 | 18 | 18 | — | #5,336 |
| 2021 | 32 | 32 | — | #3,547 |
| 2020 | 25 | 25 | — | #4,092 |
| 2019 | 23 | 23 | — | #4,417 |
| 2018 | 20 | 20 | — | #4,853 |
| 2017 | 27 | 27 | — | #3,936 |
| 2016 | 33 | 33 | — | #3,401 |
| 2015 | 28 | 28 | — | #3,835 |
| 2014 | 31 | 31 | — | #3,510 |
| 2013 | 33 | 33 | — | #3,308 |
| 2012 | 28 | 28 | — | #3,759 |
| 2011 | 28 | 28 | — | #3,741 |
| 2010 | 22 | 22 | — | #4,455 |
| 2009 | 15 | 15 | — | #5,973 |
| 2008 | 30 | 30 | — | #3,611 |
| 2007 | 22 | 22 | — | #4,446 |
| 2006 | 34 | 34 | — | #3,192 |
| 2005 | 28 | 28 | — | #3,496 |
| 2004 | 41 | 41 | — | #2,623 |
| 2003 | 36 | 36 | — | #2,761 |
| 2002 | 25 | 25 | — | #3,516 |
| 2001 | 20 | 20 | — | #4,052 |
| 2000 | 23 | 23 | — | #3,594 |
| 1999 | 36 | 36 | — | #2,496 |
| 1998 | 26 | 26 | — | #3,060 |
| 1997 | 46 | — | — | #1,982 |
| 1996 | 21 | — | — | #3,349 |
| 1995 | 17 | — | — | #3,778 |
| 1994 | 7 | — | — | #7,412 |
| 1993 | 18 | — | #12,652 | #4,883 |
| 1992 | 6 | — | — | #8,003 |
| 1991 | 5 | — | — | #8,972 |
| 1990 | 12 | — | #14,128 | #6,850 |
| 1989 | 5 | — | #13,471 | — |
| 1988 | 6 | — | — | #6,893 |
| 1987 | 6 | — | — | #6,577 |
| 1983 | 5 | — | #11,121 | — |
| 1982 | 14 | — | #8,692 | #5,343 |
| 1981 | 6 | — | #9,715 | — |
| 1979 | 5 | — | — | #6,588 |
| 1977 | 5 | — | — | #6,385 |
| 1975 | 7 | — | — | #4,579 |
| 1974 | 9 | — | — | #3,714 |
| 1973 | 5 | — | — | #5,515 |
| 1972 | 7 | — | — | #4,229 |
| 1971 | 5 | — | — | #5,318 |
| 1970 | 6 | — | — | #4,510 |