Isiah has been given to about 24,721 people in the United States since 1880. It was most common in 2001, which makes it a millennial-parent name.
Its best year was 2001, when 822 babies were given the name, ranking 336th. The typical living American called Isiah is about 26 years old today. It is relatively most common in Arizona, where it accounts for 0.01% of births.
Source: US Social Security Administration, national and state name files, 2025 release, and the Office for National Statistics for England and Wales. Etymology researched and written by our editors. Living-population and median-age figures are our own estimates, described in the methodology.