In 2025, 113 US girls were named Milly, making it the 1,790th most common girls’ name of the year, up 13 places from #1,803 in 2024. That is 1 more than the 112 girls named Milly in 2024. Its best rank for girls was #714, reached in 1884. The most girls given the name in a single year was 129, in 2014. For comparison, it was #2,160 in 2015 and #3,364 in 1950.
Social Security card records list Milly in 123 years of the 146 from 1880 to 2025, starting in 1884 with 10 babies. In all, 3,347 US babies have been given the name, all of them girls. Its busiest decade was the 2010s, with 1,024 babies named Milly.
Over the 10 years from 2016 to 2025, 1,100 US girls were named Milly; the busiest of those years was 2021, with 119. In 2025 that was about 1 in 14,224 of the girls in SSA’s list for the year.
Among the states, Milly ranked highest in Oklahoma in 2025, at #677 for girls there. It was not in the top 100 of any state. Related spellings in the SSA files include Mildred (452,998 babies since 1880), Millie (46,138 babies since 1880), Millicent (11,825 babies since 1880) and Milla (2,136 babies since 1880). Rarer spellings such as Meyly are summarised on this page.