1916Peak 20092025
Quick answers about Brennan
How many people are named Brennan?
An estimated 32,609 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 appeared 4.9× more often than the national baseline in the 2020s.
Diaspora map
Brennan broke out in Louisiana, Minnesota, and Utah (1987) and became over-represented in 24 states over 23 years.
Broke out: Louisiana, Minnesota, and Utah, 1987 · over-represented in 24 states over 23 years
Origin
≤5 yrs
≤15 yrs
16+ yrs
No breakout
