Teagan carries 28,515 cumulative American girls on SSA record and currently sits at rank 333, with a 2016 peak. The chart traces a 21st-century Celtic-import arc: virtually no presence before the late 1990s, sharp climb across the 2000s as American parents adopted Irish-derived surnames as girls' names, peak around 2016, and a gentle decline across the late 2010s and early 2020s.
The Irish source
Teagan derives from the Irish surname Mac Tadhgain, the patronymic of Tadhg, a traditional Irish given name traditionally read as "poet" or "philosopher." The surname-to-given-name conversion is purely modern American, with no historical Irish use as a female given name. Tadhg itself is overwhelmingly masculine in Ireland, and the feminine Teagan reading is an American development that took the surname spelling and assigned it female-gendered use.
The unisex masculine reading still exists in low numbers. Some American families use Teagan for boys following the Irish surname tradition, and the gender split divides roughly along family heritage and naming aesthetic preference. The female reading now dominates by a large margin in current SSA data.
The Celtic-surname cluster
Teagan sits inside the broader cluster of Irish-derived surnames adopted as American girls' names: Reagan, Riley, Quinn, Rowan, and Keegan all share the same trajectory and the same broadly Celtic register. The cluster reflects an American parental preference for surname-feeling girls' names that read as professional, slightly androgynous, and culturally distinctive. Browse the broader Irish girl names set, alongside Riley.
The counter-reading
The Teagan-versus-Tegan-versus-Taegan spelling fragmentation is real. All three spellings appear in active American use, with Teagan the most common, Tegan the older Welsh spelling, and Taegan a modern American respelling. The bearer will spend a lifetime confirming which version her parents chose. The pronunciation also forks slightly: TEE-gan is the dominant American reading, while TAY-gan surfaces occasionally.
The Irish-language gender problem deserves honest acknowledgment. Irish speakers and Irish-heritage families may read the female use of Tadhg-derived names as cultural appropriation rather than as homage, and the disconnect between the surname's Irish-language meaning (poet, philosopher, masculine) and the American female adoption is a real cultural friction that informed Irish bearers will sometimes flag.
Sibling pairings work across the Celtic-surname cluster: Teagan and Riley, Teagan and Quinn, Teagan and Rowan, Teagan and Keira. Middle names tend traditional and shorter: Teagan Rose, Teagan Marie, Teagan Grace, Teagan Jane. See where she sits on current SSA rankings.