Brennan is a distinctive boys' name in England & Wales, ranking #2266 in 2019 with 9 recorded births. The name reached its all-time peak in 2002 with 37 births ranking #559. Since 1996, the popularity has decreased by 55.0%. In 2019, approximately 1 in every 33,762 boys born was named Brennan. RISING Recent data shows the name is currently rising.