Fewer than five US boys were named Rudolf in 2025, so it does not appear in that year’s SSA list for boys. Its best rank for boys was #720, reached in 1927. That year also had the most boys given the name: 82. For comparison, it was unranked (under five boys) in 2015 and #1,121 in 1950.
Social Security card records list Rudolf in 123 years of the 146 from 1880 to 2025, starting in 1882 with 5 babies. In all, 2,951 US babies have been given the name, all of them boys. Its busiest decade was the 1920s, with 585 babies named Rudolf.
Over the 10 years from 2016 to 2025, 63 US boys were named Rudolf; the busiest of those years was 2022, with 8.
Related spellings in the SSA files include Rudolph (53,638 babies since 1880), Rudy (51,402 babies since 1880), Rodolfo (33,856 babies since 1880) and Rudolfo (2,263 babies since 1880).