Sofia is the Greek word for "wisdom" and the spelling used in Italy, Spain, Portugal and Scandinavia, while Sophia is the usual English form. Both spellings are counted separately by the Social Security Administration, which is why they share the top 10. Sofia rose from number 161 in 2000 to the top 100 in 2003 and entered the top 10 in 2024, reaching ninth place in 2025.