Meaning and history
Cassidy comes from an Irish surname, Anglicized from Ó Caiside and derived from the byname Caiside. Almost unknown as a given name before the 1970s, it became established in the 1980s and rose sharply in popularity during the 1990s.
20062006: 1,771 births, rank #199
2007: 1,657 births, rank #207
2008: 1,491 births, rank #228
2009: 1,360 births, rank #244
2010: 1,286 births, rank #250
20112011: 1,126 births, rank #282
2012: 1,140 births, rank #280
2013: 1,276 births, rank #250
2014: 1,311 births, rank #247
2015: 1,236 births, rank #257
20162016: 1,123 births, rank #289
2017: 1,003 births, rank #326
2018: 869 births, rank #361
2019: 865 births, rank #368
2020: 765 births, rank #411
20212021: 655 births, rank #478
2022: 661 births, rank #478
2023: 620 births, rank #495
2024: 646 births, rank #478
20252025: 558 births, rank #541
Cassidy moved from #478 to #541 for girls between 2024 and 2025. Its highest annual birth count came in 1999, with 3,395 births.