Nilsa has been given to about 1,809 people in the United States since 1880. It was most common in 1960, which makes it a boomer-era name.
Its best year was 1960, when 76 babies were given the name, ranking 1260th. The typical living American called Nilsa is about 58 years old today.
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.