Semaj has been given to about 9,459 people in the United States since 1880. It was most common in 2009, which makes it a millennial-parent name.
Its best year was 2009, when 495 babies were given the name, ranking 1685th. The typical living American called Semaj is about 17 years old today. It is relatively most common in Mississippi, where it accounts for 0.05% 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.