In 2025, 437 US boys were named Kasai, making it the 639th most common boys’ name of the year, up 1,108 places from #1,747 in 2024. That is 342 more than the 95 boys named Kasai in 2024. Its best rank for boys was #639, reached in this year, 2025. That year also had the most boys given the name: 437. For comparison, it was #5,876 in 2015 and unranked in 1950.
Social Security card records list Kasai in 28 years of the 146 from 1880 to 2025, starting in 1996 with 5 babies. In all, 1,083 US babies have been given the name, 1.7% of them girls and 98% boys. Its busiest decade was the 2020s, with 762 babies named Kasai.
Over the 10 years from 2016 to 2025, 897 US boys were named Kasai; the busiest of those years was 2025, with 437. In 2025 that was about 1 in 3,909 of the boys in SSA’s list for the year.
Among the states, Kasai ranked highest in Delaware in 2025, at #118 for boys there. It was not in the top 100 of any state. Rarer spellings such as Kaysa, Casai and Kazai are summarised on this page.