In 2025, 22 US boys were named Isac, making it the 4,600th most common boys’ name of the year, down 478 places from #4,122 in 2024. That is 4 fewer than the 26 boys named Isac in 2024. Its best rank for boys was #1,016, reached in 1892. The most boys given the name in a single year was 148, in 2006. For comparison, it was #2,826 in 2015 and #3,922 in 1950.
Social Security card records list Isac in 102 years of the 146 from 1880 to 2025, starting in 1884 with 5 babies. In all, 3,203 US babies have been given the name, all of them boys. Its busiest decade was the 2000s, with 1,210 babies named Isac.
Over the 10 years from 2016 to 2025, 289 US boys were named Isac; the busiest of those years was 2017, with 39. In 2025 that was about 1 in 77,640 of the boys in SSA’s list for the year.
Related spellings in the SSA files include Isaac (332,292 babies since 1880), Isaak (4,271 babies since 1880), Izaak (2,889 babies since 1880) and Izaac (2,845 babies since 1880). Rarer spellings such as Izic and Izach are summarised on this page.