The baby name Brennan appears in baby name data for the United States from 1966 to 2024. It was most popular in 2009 with 1,762 babies given the name.
In the later years of this period, Brennan has become more popular compared with earlier years.
| Year | Count |
|---|---|
| 1966 | 15 |
| 1968 | 14 |
| 1969 | 11 |
| 1971 | 11 |
| 1972 | 6 |
| 1973 | 16 |
| 1974 | 16 |
| 1975 | 34 |
| 1976 | 75 |
| 1977 | 35 |
| 1978 | 62 |
| 1979 | 74 |
| 1980 | 5 |
| 1980 | 68 |
| 1981 | 67 |
| 1982 | 91 |
| 1983 | 115 |
| 1984 | 6 |
| 1984 | 164 |
| 1985 | 215 |
| 1986 | 10 |
| 1986 | 207 |
| 1987 | 386 |
| 1988 | 403 |
| 1989 | 445 |
| 1990 | 610 |
| 1991 | 10 |
| 1991 | 737 |
| 1992 | 747 |
| 1993 | 20 |
| 1993 | 665 |
| 1994 | 29 |
| 1994 | 840 |
| 1995 | 10 |
| 1995 | 1,050 |
| 1996 | 24 |
| 1996 | 958 |
| 1997 | 6 |
| 1997 | 1,034 |
| 1998 | 33 |
| 1998 | 1,160 |
| 1999 | 1,274 |
| 2000 | 1,254 |
| 2001 | 25 |
| 2001 | 1,236 |
| 2002 | 5 |
| 2002 | 1,217 |
| 2003 | 10 |
| 2003 | 1,267 |
| 2004 | 31 |
| 2004 | 1,254 |
| 2005 | 1,290 |
| 2006 | 26 |
| 2006 | 1,370 |
| 2007 | 37 |
| 2007 | 1,356 |
| 2008 | 57 |
| 2008 | 1,586 |
| 2009 | 37 |
| 2009 | 1,762 |
| 2010 | 19 |
| 2010 | 1,509 |
| 2011 | 33 |
| 2011 | 1,348 |
| 2012 | 12 |
| 2012 | 1,224 |
| 2013 | 29 |
| 2013 | 1,080 |
| 2014 | 5 |
| 2014 | 920 |
| 2015 | 876 |
| 2016 | 7 |
| 2016 | 705 |
| 2017 | 6 |
| 2017 | 548 |
| 2018 | 430 |
| 2019 | 12 |
| 2019 | 375 |
| 2020 | 5 |
| 2020 | 301 |
| 2021 | 275 |
| 2022 | 215 |
| 2023 | 146 |
| 2024 | 6 |
| 2024 | 189 |