Dennis has been given to about 623,692 people in the United States since 1880. It was most common in 1952, which makes it a midcentury name.
Dennis ranks 707th among American boys in 2025, with 381 born that year. Its best year was 1952, when 24,605 babies were given the name, ranking 18th. The typical living American called Dennis is about 70 years old today. It is relatively most common in Nebraska, where it accounts for 0.04% 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.