An estimated 32,485 living Americans are named Brennan.
How rare is Brennan?
Brennan is uncommon among babies today, with 226 boys receiving the name in 2025, down 84.6% from its 2009 peak.
How old is the typical Brennan?
The median age of a living American named Brennan is approximately 23 years, with most bearers falling between 16 and 30 years old.
Is Brennan still popular?
Not especially. Brennan has been declining since its 2009 peak and registered 226 births in 2025.
Where is Brennan most common?
Brennan has its strongest geographic signal in Louisiana, where it appears 5.0× more often than the national baseline.
1916Peak 20092025
Peak year
2009
Decline from peak
84.6%
2025
226
All-time
33,258
Diaspora map
Brennan broke out in Hawaii, Idaho, Iowa, Kentucky, Louisiana, Michigan, Minnesota, Mississippi, Missouri, Nebraska, Oregon, Utah, Washington, and West Virginia (1994) and became over-represented in 38 states over 20 years.
Broke out: Hawaii, Idaho, Iowa, Kentucky, Louisiana, Michigan, Minnesota, Mississippi, Missouri, Nebraska, Oregon, Utah, Washington, and West Virginia, 1994 · over-represented in 38 states over 20 years
