Unknown has been given to about 19,714 people in the United States since 1880. It was most common in 1954, which makes it a midcentury name.
Its best year was 1954, when 1,192 babies were given the name, ranking 336th. The typical living American called Unknown is about 68 years old today. It is relatively most common in Oregon, where it accounts for 0.21% of births.
Source: US Social Security Administration, national and state name files, 2025 release. Etymology researched and written by our editors. Living-population and median-age figures are our own estimates, described in the methodology.