Meaning and history
From the Irish surname Anglicized from Irish Gaelic Ó Braonáin, Brennan comes from the byname Braonán, formed from braon meaning “rain, moisture, drop” with a diminutive suffix. As a given name, it has been used since the 1960s as an alternative to Brendan or Brandon, though it has been less popular than either.
20062006: 1,116 births, rank #299
2007: 1,207 births, rank #286
2008: 1,316 births, rank #263
2009: 1,464 births, rank #242
2010: 1,279 births, rank #270
20112011: 1,177 births, rank #293
2012: 1,011 births, rank #318
2013: 927 births, rank #345
2014: 806 births, rank #387
2015: 690 births, rank #444
20162016: 549 births, rank #534
2017: 464 births, rank #585
2018: 382 births, rank #661
2019: 340 births, rank #719
2020: 315 births, rank #764
20212021: 265 births, rank #871
2022: 224 births, rank #995
2023: 213 births, rank #1,024
2024: 207 births, rank #1,057
20252025: 226 births, rank #1,002
Brennan moved from #872 to #995 for boys between 2021 and 2022. Its highest annual birth count came in 2009, with 1,464 births.