In 2025, 223 US boys were named Alfonso, making it the 1,012th most common boys’ name of the year, down 90 places from #922 in 2024. That is 28 fewer than the 251 boys named Alfonso in 2024. Its best rank for boys was #294, reached in 1929. The most boys given the name in a single year was 574, in 1991. For comparison, it was #796 in 2015 and #358 in 1950.
Social Security card records list Alfonso in 142 years of the 146 from 1880 to 2025, starting in 1881 with 6 babies. In all, 41,579 US babies have been given the name, 0.3% of them girls and 99.7% boys. Its busiest decade was the 1990s, with 5,207 babies named Alfonso.
Over the 10 years from 2016 to 2025, 2,396 US boys were named Alfonso; the busiest of those years was 2017, with 279. In 2025 that was about 1 in 7,660 of the boys in SSA’s list for the year.
Among the states, Alfonso ranked highest in Texas in 2025, at #526 for boys there. It was not in the top 100 of any state. Related spellings in the SSA files include Alphonso (15,214 babies since 1880), Alonso (12,231 babies since 1880), Alphonse (10,590 babies since 1880) and Alfonzo (5,783 babies since 1880). Rarer spellings such as Alfons, Ildefonso and Alphons are summarised on this page.